Provided by: mono-runtime-common_6.8.0.105+dfsg-3.2_amd64 bug


       mono - Mono's ECMA-CLI native code generator (Just-in-Time and Ahead-of-Time)


       mono [options] file [arguments...]

       mono-sgen [options] file [arguments...]


       mono  is a runtime implementation of the ECMA Common Language Infrastructure.  This can be
       used to run ECMA and .NET applications.

       The runtime loads the specified file and optionally passes the arguments to it.  The  file
       is an ECMA assembly.  They typically have a .exe or .dll extension.

       These  executables  can  reference  additional  functionality  in  the  form  of  assembly
       references.   By  default  those  assembly  references  are  resolved  as   follows:   the
       mscorlib.dll  is  resolved  from  the system profile that is configured by Mono, and other
       assemblies are loaded from the Global Assembly Cache (GAC).

       The runtime contains a native code  generator  that  transforms  the  Common  Intermediate
       Language into native code.

       The  code  generator can operate in two modes: Just-in-time compilation (JIT) or Ahead-of-
       time compilation (AOT).  Since code can be dynamically loaded, the runtime environment and
       the JIT are always present, even if code is compiled ahead of time.

       The  runtime  provides  a  number  of  configuration options for running applications, for
       developing and debugging, and for testing and debugging the runtime itself.

       The mono command uses the moving and generational SGen garbage collector while  the  mono-
       boehm command uses the conservative Boehm garbage collector.


       On Unix-based systems, Mono provides a mechanism to emulate the Windows-style file access,
       this includes providing a case insensitive view of the file  system,  directory  separator
       mapping (from \ to /) and stripping the drive letters.

       This  functionality  is  enabled  by setting the MONO_IOMAP environment variable to one of
       all, drive and case.

       See the description for MONO_IOMAP in the environment variables section for more details.


       A number of diagnostic command line options take as argument  a  method  description.    A
       method  description  is  a  textual representation that can be used to uniquely identify a
       method.   The syntax is as follows:

       The values in brackets are optional, like the namespace and the arguments.   The arguments
       themselves  are either empty, or a comma-separated list of arguments.   Both the classname
       and methodname can be set to the special value '*' to match any values (Unix  shell  users
       should escape the argument to avoid the shell interpreting this).

       The  arguments,  if  present  should  be  a  comma  separated  list of types either a full
       typename, or for built-in types it should use the  low-level  ILAsm  type  names  for  the
       built-in types, like 'void', 'char', 'bool', 'byte', 'sbyte', 'uint16', 'int16', 'uint',

       Pointer  types  should  be  the  name of the type, followed by a '*', arrays should be the
       typename followed by '[' one or more commas (to indicate the rank of the array), and ']'.

       Generic values should use '<', one or more type names, separated by both  a  comma  and  a
       space and '>'.

       By-reference arguments should include a "&" after the typename.

       *:ctor(int)         // All constructors that take an int as an argument
       *:Main              // Methods named Main in any class
       *:Main(string[])    // Methods named Main that take a string array in any class


       The following options are available:

       --aot, --aot[=options]
              This  option is used to precompile the CIL code in the specified assembly to native
              code.  The generated code is stored in a file with the extension  .so.   This  file
              will  be  automatically  picked  up  by  the runtime when the assembly is executed.
              Ahead-of-Time compilation is most useful if you use  it  in  combination  with  the
              -O=all,-shared flag which enables all of the optimizations in the code generator to
              be performed.  Some of those  optimizations  are  not  practical  for  Just-in-Time
              compilation  since  they  might be very time consuming.  Unlike the .NET Framework,
              Ahead-of-Time compilation will not generate domain independent code:  it  generates
              the   same  code  that  the  Just-in-Time  compiler  would  produce.    Since  most
              applications use a single domain, this is fine.    If  you  want  to  optimize  the
              generated  code  for use in multi-domain applications, consider using the -O=shared
              flag.  This pre-compiles the methods, but the original assembly is  still  required
              to execute as this one contains the metadata and exception information which is not
              available on the generated file.  When precompiling code, you might want to compile
              with  all  optimizations (-O=all).  Pre-compiled code is position independent code.
              Precompilation is just a mechanism to reduce startup time,  increase  code  sharing
              across  multiple  mono processes and avoid just-in-time compilation program startup
              costs.  The original assembly must still be present, as the metadata  is  contained
              there.   AOT  code  typically  can  not be moved from one computer to another (CPU-
              specific optimizations that are detected at runtime) so you should not try to  move
              the   pre-generated   assemblies   or  package  the  pre-generated  assemblies  for
              deployment.  A few options are available as a parameter to the --aot  command  line
              option.   The options are separated by commas, and more than one can be specified:

                     Instructs  the  AOT  compiler  to  output assembly code instead of an object

                     If specified, forces the generated AOT files to  be  bound  to  the  runtime
                     version  of the compiling Mono.   This will prevent the AOT files from being
                     consumed by a different Mono runtime.

                     This instructs the AOT code generator to output certain data constructs into
                     a separate file.   This can reduce the executable images some five to twenty
                     percent.   Developers need to then ship the resulting aotdata as a  resource
                     and   register   a   hook   to   load  the  data  on  demand  by  using  the
                     mono_install_load_aot_data_hook method.

                     When this option is specified, icalls (internal calls made from the standard
                     library  into  the  mono runtime code) are invoked directly instead of going
                     through the operating system symbol lookup operation.  This requires use  of
                     the static option.

                     When this option is specified, P/Invoke methods are invoked directly instead
                     of going  through  the  operating  system  symbol  lookup  operation.   This
                     requires use of the static option.

                     Instructs  the  AOT  compiler to emit DWARF debugging information. When used
                     together with the  nodebug  option,  only  DWARF  debugging  information  is
                     emitted, but not the information that can be used at runtime.

              full   This creates binaries which can be used with the --full-aot option.

              hybrid This creates binaries which can be used with the --hybrid-aot option.

              llvm   AOT  will  be  performed  with  the LLVM backend instead of the Mono backend
                     where possible. This will be slower to compile but most likely result  in  a
                     performance improvement.

                     AOT will be performed with the LLVM backend exclusively and the Mono backend
                     will not be used. The only output in this mode  will  be  the  bitcode  file
                     normally   specified   with   the   llvm-outfile  option.  Use  of  llvmonly
                     automatically  enables  the  full  and  llvm  options.   This   feature   is

                     Use this option to add more flags to the built-in set of flags passed to the
                     LLVM optimizer.   When you invoke the mono command with  the  --aot=llvm  it
                     displays the current list of flags that are being passed to the opt command.
                     The list of possible flags that can be passed can be obtained by calling the
                     bundled opt program that comes with Mono, and calling it like this:

                          opt --help

                     Use this option to add more flags to the built-in set of flags passed to the
                     LLVM static compiler (llc).   The list of possible flags that can be  passed
                     can be obtained by calling the bundled llc program that comes with Mono, and
                     calling it like this:

                          llc --help

              mcpu=[native o generic]
                     cpu=native allows AOT mode to use all  instructions  current  CPU  supports,
                     e.g.  AVX2,  SSE42,  etc.   Default value is 'generic'.  mattr=[cpu feature]
                     Allows AOT code generator to  use  specified  CPU  features  where  possible
                     including  `System.Runtime.Intrinsics.*'.   E.g.  `mattr=+avx2,mattr=-lzcnt'
                     unlocks sse1-4.2,  avx1-2  and  disables  lzcnt.   It's  useful  for  cross-
                     compilation  or  when it's not possible to use `-mcpu=native' (which enables
                     all cpu feature current cpu has).  llvm-outfile=[filename]  Gives  the  path
                     for  the  temporary  LLVM  bitcode  file created during AOT.  dedup Each AOT
                     module will typically contain the code for  inflated  methods  and  wrappers
                     that  are called by code in that module. In dedup mode, we identify and skip
                     compiling all of those methods. When using this mode  with  fullaot,  dedup-
                     include is required or these methods will remain missing.

                     In  dedup-include  mode,  we are in the pass of compilation where we compile
                     the methods that we had previously skipped. All of them are emitted into the
                     assembly  that  is  passed as this option. We consolidate the many duplicate
                     skipped copies of the same method into one.

              info   Print the architecture the AOT in this copy of Mono targets and quit.

              interp Generates all required wrappers, so that it is possible to run --interpreter
                     without  any  code generation at runtime.  This option only makes sense with
                     mscorlib.dll.  Embedders can set

                     Outputs a gcc -M style dependency file.

                     mono_jit_set_aot_mode (MONO_AOT_MODE_INTERP);

                     Additional flags to pass to the C linker (if the current AOT mode calls  for
                     invoking it).

                     Same for the llvm tools 'opt' and 'llc'.

                     Instructs  the AOT compiler to generate offline sequence points .msym files.
                     The generated .msym files will be stored into a subfolder of <PATH> named as
                     the compilation AOTID.

                     Use  the  GNU style target triple <TRIPLE> to determine some code generation
                     options, i.e.  --mtriple=armv7-linux-gnueabi will generate code that targets
                     ARMv7.  This  is  currently only supported by the ARM backend. In LLVM mode,
                     this triple is passed on to the LLVM llc compiler.

                     When compiling in full aot mode, the IMT trampolines must be  precreated  in
                     the  AOT  image.   You  can  add  additional  method  trampolines  with this
                     argument.  Defaults to 512.

                     When compiling in full aot mode, the value type generic sharing  trampolines
                     must  be  precreated  in  the  AOT  image.   You  can  add additional method
                     trampolines with this argument.  Defaults to 512.

                     Instructs the AOT compiler to not output any debugging information.

                     This prevents the AOT compiler from generating a direct calls to  a  method.
                     The  AOT compiler usually generates direct calls for certain methods that do
                     not require going through the PLT (for example, methods that  are  known  to
                     not  require  a hook like a static constructor) or call into simple internal

                     When compiling in full aot mode, the generic  sharing  trampolines  must  be
                     precreated in the AOT image.  You can add additional method trampolines with
                     this argument.  Defaults to 4096.

                     When compiling in full aot mode, the generic sharing fetch trampolines  must
                     be  precreated  in the AOT image.  You can add additional method trampolines
                     with this argument.  Defaults to 128.

                     When compiling in full aot mode, the method trampolines must  be  precreated
                     in  the  AOT  image.   You  can  add additional method trampolines with this
                     argument.  Defaults to 4096.

                     Instructs the AOT compiler to save the output to the specified file.

                     If the AOT compiler cannot compile a method for any  reason,  enabling  this
                     flag will output the skipped methods to the console.

                     Specify  a file to use for profile-guided optimization. See the AOT profiler
                     sub-section. To specify multiple files, include the profile option  multiple

                     AOT  *only*  the  methods  described in the files specified with the profile
                     option. See the AOT profiler sub-section.

                     Override  the  value  of  a  static  readonly  field.  Usually,  during  JIT
                     compilation, the static constructor is ran eagerly, so the value of a static
                     readonly field is known at compilation time and the compiler can do a number
                     of  optimizations  based  on it. During AOT, instead, the static constructor
                     can't be ran, so this option can be used to set the value of  such  a  field
                     and enable the same set of optimizations.  Type can be any of i1, i2, i4 for
                     integers of the respective sizes  (in  bytes).   Note  that  signed/unsigned
                     numbers  do  not  matter  here,  just  the storage size.  This option can be
                     specified multiple times and it doesn't prevent the static  constructor  for
                     the  type  defining  the  field  to  execute with the usual rules at runtime
                     (hence possibly computing a different value for the field).

                     Instructs the AOT compiler to keep temporary files.

                     This instructs the compiler to generate sequence  point  checks  that  allow
                     Mono's  soft  debugger to debug applications even on systems where it is not
                     possible  to  set  breakpoints  or  to   single   step   (certain   hardware
                     configurations like the cell phones and video gaming consoles).

              static Create  an  ELF  object  file (.o) or .s file which can be statically linked
                     into an executable when embedding the mono  runtime.  When  this  option  is
                     used, the object file needs to be registered with the embedded runtime using
                     the mono_aot_register_module  function  which  takes  as  its  argument  the
                     mono_aot_module_<ASSEMBLY NAME>_info global symbol from the object file:

                     extern void *mono_aot_module_hello_info;

                     mono_aot_register_module (mono_aot_module_hello_info);

              stats  Print various stats collected during AOT compilation.

                     Explicitly  specify  path  to  store  temporary  files  created  during  AOT

                     This is an experimental option for the AOT compiler to use multiple  threads
                     when compiling the methods.

                     Prepends  <PREFIX>  to  the  name  of  tools  ran  by the AOT compiler, i.e.
                     'as'/'ld'. For example, --tool=prefix=arm-linux-gnueabi- will make  the  AOT
                     compiler run

                     Prints additional information about type loading failures.

                     Instructs the AOT compiler to emit (or not emit) debug symbol information.

              no-opt Instructs the AOT compiler tot no call opt when compiling with LLVM.

              For more information about AOT, see:

              List of additional directories to search for AOT images.

              Apply  the assembly bindings from the specified configuration file when running the
              AOT compiler.  This  is  useful  when  compiling  an  auxiliary  assembly  that  is
              referenced  by a main assembly that provides a configuration file.  For example, if
              app.exe  uses  lib.dll  then  in  order  to  make  the   assembly   bindings   from
              app.exe.config available when compiling lib.dll ahead of time, use:
                   mono --apply-bindings=app.exe.config --aot lib.dll

              If  mode  is strict, Mono will check that the public key token, culture and version
              of a candidate assembly matches the requested strong name.  If mode is  legacy,  as
              long  as  the  name  matches, the candidate will be allowed. strict is the behavior
              consistent with .NET Framework but may break some existing mono-based applications.
              The default is legacy.

              Currently  the only option supported by this command line argument is disable which
              disables the attach functionality.

       --config filename
              Load the specified configuration file instead of the default one(s).   The  default
              files  are  /etc/mono/config  and  ~/.mono/config  or  the  file  specified  in the
              MONO_CONFIG environment variable, if set.  See  the  mono-config(5)  man  page  for
              details on the format of this file.

              This  instructs the Mono runtime to start a debugging agent inside the Mono runtime
              and connect it to a client user interface will  control  the  Mono  process.   This
              option is typically used by IDEs, like the MonoDevelop or Visual Studio IDEs.
              The configuration is specified using one of more of the following options:

                            Use  this option to specify the IP address where your debugger client
                            is listening to.

                            Specifies the diagnostics log level for

                            Used to specify the file where the log will be stored, it defaults to
                            standard output.

                            Defaults to no, with the default option Mono will actively connect to
                            the host/port configured with the address option.  If you set  it  to
                            'y', it instructs the Mono runtime to start debugging in server mode,
                            where Mono actively waits for the debugger front end  to  connect  to
                            the  Mono  process.  Mono will print out to stdout the IP address and
                            port where it is listening.

                            If set to yes, Mono will call  setpgid(0,  0)  on  startup,  if  that
                            function is available on the system. This is useful for ensuring that
                            signals delivered to a process that is executing the debuggee are not
                            propagated  to the debuggee, e.g. when Ctrl-C sends SIGINT to the sdb

                            Defaults to yes, with the default option Mono will suspend the vm  on
                            startup  until  it connects successfully to a debugger front end.  If
                            you set it to 'n', in conjunction with  server=y,  it  instructs  the
                            Mono  runtime to run as normal, while caching metadata to send to the
                            debugger front end on connection..

                            This is used to specify the transport that the debugger will  use  to
                            communicate.   It must be specified and currently requires this to be

                     Configures the virtual machine to be better suited for desktop applications.
                     Currently  this  sets  the  GC system to avoid expanding the heap as much as
                     possible at the expense of slowing down garbage collection a bit.

                     This flag instructs the Mono runtime to not generate any code at runtime and
                     depend  exclusively  on  the  code  generated  from  using  mono  --aot=full
                     previously.  This is useful for platforms that do not  permit  dynamic  code
                     generation,  or  if you need to run assemblies that have been stripped of IL
                     (for example using mono-cil-strip).  Notice that  this  feature  will  abort
                     execution  at  runtime  if  a  codepath  in  your  program,  or Mono's class
                     libraries attempts to generate  code  dynamically.   You  should  test  your
                     software upfront and make sure that you do not use any dynamic features.

                     Same as --full-aot with fallback to the interpreter.

              --gc=boehm, --gc=sgen
                     Selects  the  Garbage  Collector  engine  for  Mono  to  use, Boehm or SGen.
                     Currently this merely ensures that you are running either the mono or  mono-
                     sgen  commands.     This flag can be set in the MONO_ENV_OPTIONS environment
                     variable to force all of your child processes to use one particular kind  of
                     GC with the Mono runtime.

                     Command line equivalent of the MONO_GC_DEBUG environment variable.

                     Command line equivalent of the MONO_GC_PARAMS environment variable.

              --arch=32, --arch=64
                     (Mac  OS X only): Selects the bitness of the Mono binary used, if available.
                     If the binary used is already for the selected bitness, nothing changes.  If
                     not,  the  execution  switches  to a binary with the selected bitness suffix
                     installed side by side (for example, '/bin/mono --arch=64'  will  switch  to
                     '/bin/mono64' iff '/bin/mono' is a 32-bit build).

              --help, -h
                     Displays usage instructions.

                     The  Mono runtime will use its interpreter to execute a given assembly.  The
                     interpreter is usually slower  than  the  JIT,  but  it  can  be  useful  on
                     platforms where code generation at runtime is not allowed.

                     This  flag allows the Mono runtime to run assemblies that have been stripped
                     of IL, for example using mono-cil-strip. For this to work, the assembly must
                     have been AOT compiled with --aot=hybrid.

                     This  flag  is  similar to --full-aot, but it does not disable the JIT. This
                     means you can use dynamic features such as System.Reflection.Emit.

              --llvm If the Mono runtime has been compiled with LLVM support  (not  available  in
                     all configurations), Mono will use the LLVM optimization and code generation
                     engine  to  JIT  or   AOT   compile.    For   more   information,   consult:

                     This   flag  allows  Mono  and  LLVM  to  apply  aggressive  floating  point
                     optimizations.  Can break IEEE754 compliance.

                     When using a Mono that has been compiled with LLVM support, it  forces  Mono
                     to fallback to its JIT engine and not use the LLVM backend.

              --optimize=MODE, -O=MODE
                     MODE   is  a  comma  separated  list  of  optimizations.   They  also  allow
                     optimizations to be turned off by prefixing the  optimization  name  with  a
                     minus  sign.   In  general,  Mono  has  been tuned to use the default set of
                     flags, before using these flags for a deployment setting, you might want  to
                     actually  measure  the  benefits  of using them.  The following optimization
                     flags are implemented in the core engine:
                                  abcrem     Array bound checks removal
                                  all        Turn on all optimizations
                                  aot        Usage of Ahead Of Time compiled code
                                  branch     Branch optimizations
                                  cfold      Constant folding
                                  cmov       Conditional moves [arch-dependency]
                                  deadce     Dead code elimination
                                  consprop   Constant propagation
                                  copyprop   Copy propagation
                                  fcmov      Fast x86 FP compares [arch-dependency]
                                  float32     Perform 32-bit float arithmetic using 32-bit operations
                                  gshared    Enable generic code sharing.
                                  inline     Inline method calls
                                  intrins    Intrinsic method implementations
                                  linears    Linear scan global reg allocation
                                  leaf       Leaf procedures optimizations
                                  loop       Loop related optimizations
                                  peephole   Peephole postpass
                                  precomp    Precompile all methods before executing Main
                                  sched      Instruction scheduling
                                  shared     Emit per-domain code
                                  sse2       SSE2 instructions on x86 [arch-dependency]
                                  tailc      Tail recursion and tail calls
                     For example, to enable all the optimization but dead  code  elimination  and
                     inlining, you can use:
                     The  flags  that  are flagged with [arch-dependency] indicate that the given
                     option if used in combination with Ahead of Time  compilation  (--aot  flag)
                     would  produce  pre-compiled  code  that  will depend on the current CPU and
                     might not be safely moved to another computer.

                     The following optimizations are supported

                            Requests that the runtime performn 32-bit floating  point  operations
                            using  only  32-bits.    By default the Mono runtime tries to use the
                            highest precision available for floating point operations, but  while
                            this  might  render better results, the code might run slower.   This
                            options also affects the code generated by the LLVM backend.

                     inline Controls whether the runtime should attempt to inline (the  default),
                            or not inline methods invocations
              --response=FILE  Provides  a response file, this instructs the Mono command to read
              other command line options from the specified file, as  if  the  options  had  been
              specified on the command line.   Useful when you have very long command lines.

                     Mono  supports  different  runtime versions. The version used depends on the
                     program  that  is  being  run  or   on   its   configuration   file   (named
                     program.exe.config). This option can be used to override such autodetection,
                     by forcing a different runtime version to be used.  Note  that  this  should
                     only  be  used to select a later compatible runtime version than the one the
                     program was compiled against. A typical usage is for running a  1.1  program
                     on a 2.0 version:
                              mono --runtime=v2.0.50727 program.exe

                     Configures  the  virtual  machine  to be better suited for server operations
                     (currently, allows a heavier threadpool initialization).

                     Instructs Mono to generate code  using  MAP_JIT  on  MacOS.   Necessary  for
                     bundled applications.

                     Verifies  mscorlib and assemblies in the global assembly cache for valid IL,
                     and all user code for IL verifiability.

                     This is different from --security's verifiable  or  validil  in  that  these
                     options only check user code and skip mscorlib and assemblies located on the
                     global assembly cache.

              -V, --version
                     Prints JIT version information (system  configuration,  release  number  and
                     branch names if available).

                     Print version number only.


       The following options are used to help when developing a JITed application.

       --debug, --debug=OPTIONS
              Turns  on  the  debugging  mode  in  the runtime.  If an assembly was compiled with
              debugging information, it will produce line number information for stack traces.

              The optional OPTIONS argument is a  comma  separated  list  of  debugging  options.
              These  options are turned off by default since they generate much larger and slower
              code at runtime.

              The following options are supported:

              casts  Produces a detailed  error  when  throwing  a  InvalidCastException.    This
                     option  needs to be enabled as this generates more verbose code at execution

                     Disable some JIT optimizations which are usually only disabled when  running
                     inside  the  debugger.   This  can  be  helpful if you want to attach to the
                     running process with mdb.

              gdb    Generate and register debugging information with gdb. This is only supported
                     on some platforms, and only when using gdb 7.0 or later.

              Loads  a  profiler  module  with the given arguments. For more information, see the
              PROFILING section.  This option can be used multiple times; each time will load  an
              additional profiler module.

              Shows  method  names  as they are invoked.  By default all methods are traced.  The
              trace can be customized to include or exclude methods, classes  or  assemblies.   A
              trace  expression is a comma separated list of targets, each target can be prefixed
              with a minus sign to turn off a particular target.  The words `program', `all'  and
              `disabled'  have  special  meaning.   `program'  refers  to  the main program being
              executed, and `all' means all the method calls.  The `disabled' option is  used  to
              start  up with tracing disabled.  It can be enabled at a later point in time in the
              program by sending the SIGUSR2 signal to the runtime.  Assemblies are specified  by
              their name, for example, to trace all calls in the System assembly, use:

                   mono --trace=System app.exe

              Classes  are  specified with the T: prefix.  For example, to trace all calls to the
              System.String class, use:

                   mono --trace=T:System.String app.exe

              And individual methods are referenced with the M: prefix, and the  standard  method

                   mono --trace=M:System.Console:WriteLine app.exe

              Exceptions can also be traced, it will cause a stack trace to be printed every time
              an exception of the specified type is thrown.  The exception type can be  specified
              with  or  without  the namespace, and to trace all exceptions, specify 'all' as the
              type name.

                   mono --trace=E:System.Exception app.exe

              As previously noted, various rules can be specified at once:

                   mono --trace=T:System.String,T:System.Random app.exe

              You can exclude pieces, the next example traces calls to System.String  except  for
              the System.String:Concat method.

                   mono --trace=T:System.String,-M:System.String:Concat

              You can trace managed to unmanaged transitions using the wrapper qualifier:

                   mono --trace=wrapper app.exe

              Finally, namespaces can be specified using the N: prefix:

                   mono --trace=N:System.Xml

              Don't  align  stack  frames on the x86 architecture.  By default, Mono aligns stack
              frames to 16 bytes on x86, so that local floating point and SIMD variables  can  be
              properly  aligned.   This  option  turns off the alignment, which usually saves one
              instruction per call, but might result in significantly lower  floating  point  and
              SIMD performance.

              Generate  a JIT method map in a /tmp/ file. This file is then used, for
              example, by the perf tool included in recent Linux kernels.  Each line in the  file

                   HEXADDR HEXSIZE methodname

              Currently this option is only supported on Linux.


       The  maintainer  options  are  only  used  by those developing the runtime itself, and not
       typically of interest to runtime users or developers.

              This flag is used  by  the  automatic  optimization  bug  bisector.   It  takes  an
              optimization  flag and a filename of a file containing a list of full method names,
              one per line.  When it compiles one of the methods in the  file  it  will  use  the
              optimization  given,  in  addition to the optimizations that are otherwise enabled.
              Note that if the optimization is enabled by default, you  should  disable  it  with
              `-O`,  otherwise  it  will  just apply to every method, whether it's in the file or

       --break method
              Inserts   a   breakpoint   before   the   method    whose    name    is    `method'
              (namespace.class:methodname).   Use `Main' as method name to insert a breakpoint on
              the application's main method.  You can use it  also  with  generics,  for  example

              Inserts a breakpoint on exceptions.  This allows you to debug your application with
              a native debugger when an exception is thrown.

       --compile name
              This compiles a method (, this is used  for  testing  the
              compiler performance or to examine the output of the code generator.

              Compiles  all  the  methods  in  an  assembly.   This  is used to test the compiler
              performance or to examine the output of the code generator

       --graph=TYPE METHOD
              This generates a postscript file with a graph with the details about the  specified
              method  (   This  requires  `dot'  and  ghostview  to be
              installed (it expects Ghostview to be  called  "gv").   The  following  graphs  are
                        cfg        Control Flow Graph (CFG)
                        dtree      Dominator Tree
                        code       CFG showing code
                        ssa        CFG showing code after SSA translation
                        optcode    CFG showing code after IR optimizations
              Some graphs will only be available if certain optimizations are turned on.

              Instruct  the runtime on the number of times that the method specified by --compile
              (or all the methods if --compile-all is used) to be compiled.   This  is  used  for
              testing the code generator performance.

              Displays  information about the work done by the runtime during the execution of an

              Perform maintenance of the process shared data.   semdel  will  delete  the  global
              semaphore.  hps will list the currently used handles.

       -v, --verbose
              Increases  the  verbosity  level,  each  time it is listed, increases the verbosity
              level to include more information (including, for example,  a  disassembly  of  the
              native code produced, code selector info etc.).


       The  Mono  runtime  allows  external  processes  to  attach  to a running process and load
       assemblies into the running program.   To attach to the process,  a  special  protocol  is
       implemented in the Mono.Management assembly.

       With  this  support  it  is possible to load assemblies that have an entry point (they are
       created with -target:exe or -target:winexe) to be loaded and executed in the Mono process.

       The code is loaded into the root domain, and it starts execution on  the  special  runtime
       attach  thread.     The  attached  program  should create its own threads and return after

       This support allows for example debugging applications by having the csharp  shell  attach
       to running processes.


       The  Mono  runtime  includes  a  profiler API that dynamically loaded profiler modules and
       embedders can use to collect  performance-related  data  about  an  application.  Profiler
       modules are loaded by passing the --profile command line argument to the Mono runtime.

       Mono  ships  with  a  few profiler modules, of which the log profiler is the most feature-
       rich. It is also the default profiler if the profiler argument is not given, or if default
       is  given.   It  is  possible to write your own profiler modules; see the Custom profilers

   Log profiler
       The log profiler can be used to collect a lot of information about a  program  running  in
       the  Mono  runtime. This data can be used (both while the process is running and later) to
       do analyses of the program behavior, determine resource usage, performance issues or  even
       look for particular execution patterns.

       This  is  accomplished  by  logging  the  events  provided by the Mono runtime through the
       profiler API and periodically writing them to a file which can later be inspected with the
       mprof-report(1) tool.

       More  information  about how to use the log profiler is available on the mono-profilers(1)
       page, under the LOG PROFILER section, as well as the mprof-report(1) page.

   Coverage profiler
       The code coverage profiler can instrument a  program  to  help  determine  which  classes,
       methods,  code  paths,  etc are actually executed. This is most useful when running a test
       suite to determine whether the tests actually cover the code they're expected to.

       More  information  about  how  to  use  the  coverage  profiler  is   available   on   the
       mono-profilers(1) page, under the COVERAGE PROFILER section.

   AOT profiler
       The   AOT  profiler  can  help  improve  startup  performance  by  logging  which  generic
       instantiations are used by a program, which the AOT compiler can then use to compile those
       instantiations ahead of time so that they won't have to be JIT compiled at startup.

       More  information  about how to use the AOT profiler is available on the mono-profilers(1)
       page, under the AOT PROFILER section.

   Custom profilers
       Custom profiler modules can be loaded in exactly the same way as the standard modules that
       ship  with  Mono.  They  can  also  access  the  same  profiler API to gather all kinds of
       information about the code being executed.

       For example, to use a third-party profiler called custom, you would load it like this:

              mono --profile=custom program.exe

       You could also pass arguments to it:

              mono --profile=custom:arg1,arg2=arg3 program.exe

       In the above example,  Mono  will  load  the  profiler  from  the  shared  library  called      (name      varies     based     on     platform,     e.g.,
       libmono-profiler-custom.dylib on OS X).  This profiler module  must  be  on  your  dynamic
       linker library path (LD_LIBRARY_PATH on most systems, DYLD_LIBRARY_PATH on OS X).

       For   a   sample   of   how   to   write   your   own   custom   profiler,   look  at  the
       samples/profiler/sample.c file in the Mono source tree.


       To debug managed applications, you can use the mdb command, a command line debugger.

       It is possible to obtain a stack trace of all the active threads in Mono  by  sending  the
       QUIT signal to Mono, you can do this from the command line, like this:

            kill -QUIT pid

       Where  pid  is  the  Process ID of the Mono process you want to examine.  The process will
       continue running afterwards, but its state is not guaranteed.

       Important: this is a last-resort mechanism for debugging applications and  should  not  be
       used  to  monitor  or  probe a production application.  The integrity of the runtime after
       sending this signal is not guaranteed and the application might crash or terminate at  any
       given point afterwards.

       The  --debug=casts  option  can  be used to get more detailed information for Invalid Cast
       operations, it will provide information about the types involved.

       You can use the MONO_LOG_LEVEL and MONO_LOG_MASK  environment  variables  to  get  verbose
       debugging output about the execution of your application within Mono.

       The  MONO_LOG_LEVEL  environment  variable if set, the logging level is changed to the set
       value. Possible values are "error", "critical", "warning", "message", "info", "debug". The
       default  value  is "error". Messages with a logging level greater then or equal to the log
       level will be printed to stdout/stderr.

       Use "info" to track the dynamic loading of assemblies.

       Use the MONO_LOG_MASK environment variable to limit the extent of the messages you get: If
       set,  the  log  mask  is  changed  to  the  set value. Possible values are "asm" (assembly
       loader), "type", "dll" (native library loader), "gc" (garbage  collector),  "cfg"  (config
       file   loader),   "aot"   (precompiler),  "security"  (e.g.  Moonlight  CoreCLR  support),
       "threadpool" (thread pool generic), "io-selector" (async  socket  operations),  "io-layer"
       (I/O  layer  -  processes,  files, sockets, events, semaphores, mutexes and handles), "io-
       layer-process",   "io-layer-file",   "io-layer-socket",    "io-layer-event",    "io-layer-
       semaphore",  "io-layer-mutex",  "io-layer-handle"  and "all".  The default value is "all".
       Changing the mask value allows you to display only messages for a certain  component.  You
       can  use  multiple masks by comma separating them. For example to see config file messages
       and assembly loader messages set you mask to "asm,cfg".

       The following is a common use to track down problems with P/Invoke:

            $ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe


       If you are using LLDB, you can  use  the  script  to  print  some  internal  data
       structures with it.   To use this, add this to your $HOME/.lldbinit file:
       command script import $PREFIX/lib/mono/lldb/

       Where $PREFIX is the prefix value that you used when you configured Mono (typically /usr).

       Once this is done, then you can inspect some Mono Runtime data structures, for example:
       (lldb) p method

       (MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()


       Mono's  XML  serialization  engine  by  default  will  use  a reflection-based approach to
       serialize which might be slow for continuous processing (web service  applications).   The
       serialization engine will determine when a class must use a hand-tuned serializer based on
       a few parameters and if needed it will produce a customized C# serializer for  your  types
       at   runtime.    This  customized  serializer  then  gets  dynamically  loaded  into  your

       You can control this with the MONO_XMLSERIALIZER_THS environment variable.

       The possible values are `no' to disable the use of  a  C#  customized  serializer,  or  an
       integer  that  is  the  minimum  number  of  uses before the runtime will produce a custom
       serializer (0 will produce a custom serializer on the first  access,  50  will  produce  a
       serializer  on  the  50th  use).  Mono  will  fallback to an interpreted serializer if the
       serializer generation somehow fails. This behavior can be disabled by setting  the  option
       `nofallback' (for example: MONO_XMLSERIALIZER_THS=0,nofallback).


              Turns  off  the garbage collection in Mono.  This should be only used for debugging

              (Also http_proxy) If set, web  requests  using  the  Mono  Class  Library  will  be
              automatically proxied through the given URL.  Not supported on Windows, Mac OS, iOS
              or Android. See also NO_PROXY.

              When Mono is compiled with LLVM support, this instructs the runtime to  stop  using
              LLVM  after  the  specified  number  of  methods are JITed.  This is a tool used in
              diagnostics to help isolate problems in the code generation backend.   For  example
              LLVM_COUNT=10  would  only compile 10 methods with LLVM and then switch to the Mono
              JIT engine.  LLVM_COUNT=0 would disable the LLVM engine altogether.

              Mono contains a feature which  allows  modifying  settings  in  the  .config  files
              shipped  with  Mono  by  using  config section mappers. The mappers and the mapping
              rules are defined in the $prefix/etc/mono/2.0/ file and, optionally, in
              the file found in the top-level directory of your ASP.NET application.
              Both files are read by System.Web on application startup, if they are found at  the
              above  locations.  If  you  don't want the mapping to be performed you can set this
              variable in your environment before starting the application and no action will  be

              Mono  has  a cache of ConfigSection objects for speeding up WebConfigurationManager
              queries. Its default size is 100 items, and  when  more  items  are  needed,  cache
              evictions  start  happening.  If  evictions  are  too  frequent  this  could impose
              unnecessary overhead, which could be avoided by using this environment variable  to
              set up a higher cache size (or to lower memory requirements by decreasing it).

              If  set,  causes  Mono.Cairo to collect stack traces when objects are allocated, so
              that the finalization/Dispose warnings include  information  about  the  instance's

              If  set,  this  variable  overrides  the  default  system  configuration  directory
              ($PREFIX/etc). It's used to locate machine.config file.

              Sets the style of COM interop.  If the value of this variable is "MS" Mono will use
              string  marhsalling  routines  from  the liboleaut32 for the BSTR type library, any
              other values will use the mono-builtin BSTR string marshalling.

              If  set,  this  variable  overrides  the   default   runtime   configuration   file
              ($PREFIX/etc/mono/config).   The   --config  command  line  options  overrides  the
              environment variable.

              Override the automatic cpu detection mechanism. Currently used only  on  arm.   The
              format of the value is as follows:

                   "armvV [thumb[2]]"

              where  V  is the architecture number 4, 5, 6, 7 and the options can be currently be
              "thumb" or "thumb2". Example:

                   MONO_CPU_ARCH="armv4 thumb" mono ...

              When Mono is built with a soft float fallback on ARM and this variable  is  set  to
              "1", Mono will always emit soft float code, even if a VFP unit is detected.

              Fall  back on the kqueue FileSystemWatcher implementation in Darwin. The default is
              the FSEvent implementation.

              This is a debugging aid used  to  force  limits  on  the  kqueue  FileSystemWatcher
              implementation in Darwin.   There is no limit by default.

              If  this environment variable is `yes', the runtime uses unmanaged collation (which
              actually means no culture-sensitive  collation).  It  internally  disables  managed
              collation functionality invoked via the members of System.Globalization.CompareInfo
              class. Collation is enabled by default.

              Unix only: If  set,  disable  usage  of  shared  memory  for  exposing  performance
              counters.  This  means  it will not be possible to both externally read performance
              counters from this processes or read those of external processes.

              When set, enables the use of a fully managed DNS resolver instead  of  the  regular
              libc functions. This resolver performs much better when multiple queries are run in

              Note that /etc/nsswitch.conf will be ignored.

              For platforms that do not otherwise have a way of obtaining random bytes  this  can
              be  set  to  the  name  of  a file system socket on which an egd or prngd daemon is

              If set, tells mono to attempt using native asynchronous I/O services. If not set, a
              default  select/poll  implementation  is  used.  Currently  epoll  and  kqueue  are

       MONO_THREADS_SUSPEND Selects a mechanism that Mono will use to suspend
              threads.  May be set to "preemptive", "coop", or "hybrid".  Threads may need to  be
              suspended  by  the  debugger,  or using some .NET threading APIs, and most commonly
              when the SGen garbage collector needs to stop all threads during a  critical  phase
              of   garbage   collection.   Preemptive  mode  is  the  mode  that  Mono  has  used
              historically, going back to the Boehm days, where the garbage collector  would  run
              at  any point and suspend execution of all threads as required to perform a garbage
              collection.  The cooperative mode on the other hand requires the cooperation of all
              threads  to  stop  at  a  safe  point.   This  makes for an easier to debug garbage
              collector and it improves the stability of the  runtime  because  threads  are  not
              suspended  when  accessing critical resources.  In scenarios where Mono is embedded
              in another application, cooperative suspend requires the embedder  code  to  follow
              coding  guidelines  in  order to cooperate with the garbage collector.  Cooperative
              suspend in embedded Mono is currently experimental.  Hybrid mode is  a  combination
              of  the two that retains better compatability with scenarios where Mono is embedded
              in another application:  threads  that  are  running  managed  code  or  code  that
              comprises  the  Mono runtime will be cooperatively suspended, while threads running
              embedder code will be preemptively suspended.  Hybrid suspend  is  the  default  on
              some desktop platforms.

              Alternatively,  coop  and  hybrid  mode can be enabled at compile time by using the
              --enable-cooperative-suspend or --enable-hybrid-suspend flags,  respectively,  when
              calling  configure.   The  MONO_THREADS_SUSPEND environment variable takes priority
              over the compiled default.

              This environment variable is obsolete, but  retained  for  backward  compatibility.
              Use  MONO_THREADS_SUSPEND set to "coop" instead.  Note that if configure flags were
              provided to enable cooperative or hybrid suspend, this variable is ignored.

              This environment variable allows you to pass  command  line  arguments  to  a  Mono
              process  through the environment.   This is useful for example to force all of your
              Mono processes to use LLVM or SGEN without having to modify any launch scripts.

              Used to pass extra options to the debugger agent  in  the  runtime,  as  they  were
              passed using --debugger-agent=.

              Sets  the  type  of  event  log  provider to use (for System.Diagnostics.EventLog).
              Possible values are:

                     Persists event logs and entries to the local file system.  The directory  in
                     which  to persist the event logs, event sources and entries can be specified
                     as part of the value.  If the path is not explicitly  set,  it  defaults  to
                     "/var/lib/mono/eventlog" on unix and "%APPDATA%no\ventlog" on Windows.

              win32  Uses the native win32 API to write events and registers event logs and event
                     sources in the registry.   This is only available on Windows.  On Unix,  the
                     directory  permission  for individual event log and event source directories
                     is set to 777 (with +t bit) allowing everyone to read and  write  event  log
                     entries  while  only  allowing  entries  to  be  deleted by the user(s) that
                     created them.

              null   Silently discards any events.

              The default is "null" on Unix (and versions of Windows before NT), and  "win32"  on
              Windows NT (and higher).

              If  set,  contains  a  colon-separated  list  of text encodings to try when turning
              externally-generated text (e.g. command-line arguments or filenames) into  Unicode.
              The  encoding  names  come  from  the  list provided by iconv, and the special case
              "default_locale" which refers to the current locale's default encoding.

              When reading externally-generated text strings UTF-8 is tried first, and then  this
              list  is  tried  in  order  with the first successful conversion ending the search.
              When writing external text (e.g. new filenames or arguments to new  processes)  the
              first item in this list is used, or UTF-8 if the environment variable is not set.

              The  problem  with  using  MONO_EXTERNAL_ENCODINGS to process your files is that it
              results in a problem: although its possible to get the right file name  it  is  not
              necessarily  possible  to  open  the  file.   In  general if you have problems with
              encodings in your filenames you should use the "convmv" program.

              When using Mono with the SGen garbage  collector  this  variable  controls  several
              parameters  of  the  collector.   The variable's value is a comma separated list of

                     Sets the maximum size of the heap. The size is specified in bytes  and  must
                     be  a  power  of  two.  The suffixes `k', `m' and `g' can be used to specify
                     kilo-, mega- and gigabytes, respectively.  The  limit  is  the  sum  of  the
                     nursery,  major  heap  and  large object heap. Once the limit is reached the
                     application will receive OutOfMemoryExceptions when trying to allocate.  Not
                     the full extent of memory set in max-heap-size could be available to satisfy
                     a single allocation due to internal fragmentation. By default heap limits is
                     disabled and the GC will try to use all available memory.

                     Sets  the size of the nursery.  The size is specified in bytes and must be a
                     power of two.  The suffixes `k', `m' and `g' can be used to  specify  kilo-,
                     mega-  and gigabytes, respectively.  The nursery is the first generation (of
                     two).  A larger nursery will usually speed up the program but will obviously
                     use more memory.  The default nursery size 4 MB.

                     Specifies  which  major  collector  to use.  Options are `marksweep' for the
                     Mark&Sweep  collector,  `marksweep-conc'  for  concurrent   Mark&Sweep   and
                     `marksweep-conc-par' for parallel and concurrent Mark&Sweep.  The concurrent
                     Mark&Sweep collector is the default.

                     Specifies what should be the garbage collector's  target.  The  `throughput'
                     mode  aims  to  reduce  time  spent  in  the  garbage  collector and improve
                     application speed, the `pause' mode aims to keep pause times  to  a  minimum
                     and  it  receives  the  argument max-pause which specifies the maximum pause
                     time in milliseconds that is acceptable and the `balanced' mode which  is  a
                     general purpose optimal mode.

                     Once the heap size gets larger than this size, ignore what the default major
                     collection trigger metric says and only allow four nursery size's  of  major
                     heap growth between major collections.

                     Sets  the evacuation threshold in percent.  This option is only available on
                     the Mark&Sweep major collectors.  The value must be an integer in the  range
                     0  to  100.   The default is 66.  If the sweep phase of the collection finds
                     that the occupancy  of  a  specific  heap  block  type  is  less  than  this
                     percentage,  it will do a copying collection for that block type in the next
                     major collection, thereby restoring occupancy to close to  100  percent.   A
                     value of 0 turns evacuation off.

                     Enables  or  disables  lazy sweep for the Mark&Sweep collector.  If enabled,
                     the sweeping of individual major heap blocks is done piecemeal whenever  the
                     need arises, typically during nursery collections.  Lazy sweeping is enabled
                     by default.

                     Enables or disables concurrent  sweep  for  the  Mark&Sweep  collector.   If
                     enabled,  the  iteration  of all major blocks to determine which ones can be
                     freed and which ones have to be kept and swept, is  done  concurrently  with
                     the running program.  Concurrent sweeping is enabled by default.

                     Specifies  how  application threads should be scanned. Options are `precise`
                     and `conservative`. Precise marking allow the collector to know what  values
                     on  stack are references and what are not.  Conservative marking threats all
                     values as potentially references and leave them untouched.  Precise  marking
                     reduces  floating garbage and can speed up nursery collection and allocation
                     rate, it has the downside  of  requiring  a  significant  extra  memory  per
                     compiled method. The right option, unfortunately, requires experimentation.

                     Specifies  the target save ratio for the major collector. The collector lets
                     a given amount of memory to be  promoted  from  the  nursery  due  to  minor
                     collections  before  it triggers a major collection. This amount is based on
                     how much memory it expects to free. It is represented as a ratio of the size
                     of the heap after a major collection.  Valid values are between 0.1 and 2.0.
                     The default is 0.5.  Smaller values will keep the major  heap  size  smaller
                     but  will  trigger  more major collections. Likewise, bigger values will use
                     more memory and result in less frequent major collections.  This  option  is
                     EXPERIMENTAL, so it might disappear in later versions of mono.

                     Specifies  the  default allocation allowance when the calculated size is too
                     small. The allocation allowance is how much  memory  the  collector  let  be
                     promoted  before triggered a major collection.  It is a ratio of the nursery
                     size.  Valid values are between 1.0 and 10.0. The default is  4.0.   Smaller
                     values lead to smaller heaps and more frequent major collections.  Likewise,
                     bigger values will allow the heap to grow faster but use more memory when it
                     reaches  a  stable size.  This option is EXPERIMENTAL, so it might disappear
                     in later versions of mono.

                     Specifies which minor collector to use. Options are `simple' which  promotes
                     all  objects  from  the nursery directly to the old generation, `simple-par'
                     which has same promotion behavior as `simple' but using multiple workers and
                     `split' which lets objects stay longer on the nursery before promoting.

                     Specifies the ratio of memory from the nursery to be use by the alloc space.
                     This only can only be used with the split minor collector.  Valid values are
                     integers between 1 and 100. Default is 60.

                     Specifies the required age of an object must reach inside the nursery before
                     been promoted to the old generation. This only can only  be  used  with  the
                     split  minor collector.  Valid values are integers between 1 and 14. Default
                     is 2.

                     Enables or  disables  cementing.   This  can  dramatically  shorten  nursery
                     collection  times  on  some  benchmarks where pinned objects are referred to
                     from the major heap.

                     This  forbids  the  major  collector  from  performing   synchronous   major
                     collections.   The major collector might want to do a synchronous collection
                     due to excessive fragmentation. Disabling  this  might  trigger  OutOfMemory
                     error in situations that would otherwise not happen.

              When  using  Mono  with the SGen garbage collector this environment variable can be
              used to turn on various debugging features of the collector.   The  value  of  this
              variable  is  a  comma  separated  list  of  words.   Do  not  use these options in

              number Sets the debug level to the specified number.

                     After each major collection prints memory consumption for before  and  after
                     the  collection and the allowance for the minor collector, i.e. how much the
                     heap is allowed to  grow  from  minor  collections  before  the  next  major
                     collection is triggered.

                     Gathers  statistics  on  the classes whose objects are pinned in the nursery
                     and for which global remset entries are added.  Prints those statistics when
                     shutting down.


                     This  performs a remset consistency check at various opportunities, and also
                     clears the nursery at collection time, instead of the default, when  buffers
                     are  allocated  (clear-at-gc).  The consistency check ensures that there are
                     no major to minor references that are not on the remembered sets.

                     Checks that the mod-union cardtable  is  consistent  before  each  finishing
                     major  collection  pause.  This check is only applicable to concurrent major

                     Checks that mark bits in the major heap are consistent at the  end  of  each
                     major  collection.   Consistent  mark bits mean that if an object is marked,
                     all objects that it had references to must also be marked.

                     After garbage collections, check whether all vtable pointers are  no  longer

                     Performs  a  check  to  make sure that no references are left to an unloaded

                     Clears the nursery incrementally when the thread  local  allocation  buffers
                     (TLAB)  are  created.   The  default  setting clears the whole nursery at GC

                     Clears the nursery incrementally when the thread  local  allocation  buffers
                     (TLAB)  are  created,  but  at  GC time fills it with the byte `0xff`, which
                     should result in a crash more quickly  if  `clear-at-tlab-creation`  doesn't
                     work properly.

                     This clears the nursery at GC time instead of doing it when the thread local
                     allocation buffer (TLAB) is created.  The default is to clear the nursery at
                     TLAB creation time.

                     Don't  do  minor collections.  If the nursery is full, a major collection is
                     triggered instead, unless it, too, is disabled.

                     Don't do major collections.

                     Forces the GC to scan the stack conservatively, even if precise scanning  is

                     Disables the managed allocator.

                     If  set,  does a plausibility check on the scan_starts before and after each

                     If set, does a complete object walk of the nursery  at  the  start  of  each
                     minor collection.

                     If  set,  dumps  the  contents  of  the  nursery  at the start of each minor
                     collection. Requires verify-nursery-at-minor-gc to be set.

                     Dumps  the  heap  contents  to  the  specified  file.    To  visualize   the
                     information, use the mono-heapviz tool.

                     Outputs the debugging output to the specified file.   For this to work, Mono
                     needs to be compiled with the BINARY_PROTOCOL define on sgen-gc.c.   You can
                     then use this command to explore the output
                                     sgen-grep-binprot 0x1234 0x5678 < file

                     If  set, objects allocated in the nursery are suffixed with a canary (guard)
                     word, which is checked on each minor collection. Can be used to detect/debug
                     heap corruption issues.

                     If enabled, finalizers will not be run.  Everything else will be unaffected:
                     finalizable objects will still be put into the finalization queue where they
                     survive  until they're scheduled to finalize.  Once they're not in the queue
                     anymore they will be collected regularly.   If  a  list  of  comma-separated
                     class names is given, only objects from those classes will not be finalized.

                     Log verbosely around the finalization process to aid debugging.

              Provides a prefix the runtime uses to look for Global Assembly Caches.  Directories
              are separated by the platform path  separator  (colons  on  unix).  MONO_GAC_PREFIX
              should  point  to  the  top  directory  of  a prefixed install. Or to the directory
              provided      in      the       gacutil       /gacdir       command.       Example:

              Enables  some  filename rewriting support to assist badly-written applications that
              hard-code Windows paths.  Set to a colon-separated list of "drive" to  strip  drive
              letters,  or  "case"  to  do case-insensitive file matching in every directory in a
              path.  "all" enables all rewriting methods.   (Backslashes  are  always  mapped  to
              slashes if this variable is set to a valid option).
              For example, this would work from the shell:

                   export MONO_IOMAP

              If  you are using mod_mono to host your web applications, you can use the MonoIOMAP
              directive instead, like this:

                   MonoIOMAP <appalias> all

              See mod_mono(8) for more details.

              When Mono is using the LLVM code generation backend you can  use  this  environment
              variable to pass code generation options to the LLVM compiler.

              If   set  to  "disabled",  System.IO.FileSystemWatcher  will  use  a  file  watcher
              implementation which silently ignores all the watching requests.   If  set  to  any
              other   value,   System.IO.FileSystemWatcher   will   use   the   default   managed
              implementation (slow). If unset, mono will try to use inotify, FAM,  Gamin,  kevent
              under  Unix  systems  and  native API calls on Windows, falling back to the managed
              implementation on error.

              Mono supports a plugin model for its implementation of System.Messaging  making  it
              possible  to  support a variety of messaging implementations (e.g. AMQP, ActiveMQ).
              To specify which messaging implementation is to be used  the  evironement  variable
              needs  to be set to the full class name for the provider.  E.g. to use the RabbitMQ
              based AMQP implementation the variable should be set to:


              If set causes the mono process to be bound to a single processor. This may be
              useful when debugging or working around race conditions.

              Disable inlining of thread local accesses. Try setting this if you get a segfault
              early on in the execution of mono.

              Provides a search path to the runtime where to look for library
              files.   This is a tool convenient for debugging applications, but
              should not be used by deployed applications as it breaks the assembly
              loader in subtle ways.
              Directories are separated by the platform path separator (colons on unix). Example:
              Relative paths are resolved based on the launch-time current directory.
              Alternative solutions to MONO_PATH include: installing libraries into
              the Global Assembly Cache (see gacutil(1)) or having the dependent
              libraries side-by-side with the main executable.
              For a complete description of recommended practices for application
              deployment, see

              If set its the directory where the ".wapi" handle state is stored.
              This is the directory where the Windows I/O Emulation layer stores its
              shared state data (files, events, mutexes, pipes).  By default Mono
              will store the ".wapi" directory in the users's home directory.

              Uses the string value of this variable as a replacement for the host name when
              creating file names in the ".wapi" directory. This helps if the host name of
              your machine is likely to be changed when a mono application is running or if
              you have a .wapi directory shared among several different computers.
              Mono typically uses the hostname to create the files that are used to
              share state across multiple Mono processes.  This is done to support
              home directories that might be shared over the network.

              If set, extra checks are made during IO operations.  Currently, this
              includes only advisory locks around file writes.

              This environment variable controls which TLS/SSL provider Mono will
              use.  The options are usually determined by the operating system where
              Mono was compiled and the configuration options that were used for

                     Uses the default TLS stack that the Mono runtime was configured with.
                     Usually this is configured to use Apple's SSL stack on Apple
                     platforms, and Boring SSL on other platforms.

              apple  Forces the use of the Apple SSL stack, only works on Apple platforms.

              btls   Forces the use of the BoringSSL stack.    See
            for more information
                     about this stack.

              legacy This is the old Mono stack, which only supports SSL and TLS up to
                     version 1.0.   It is deprecated and will be removed in the future.

              The time, in seconds, that the SSL/TLS session cache will keep it's entry to
              avoid a new negotiation between the client and a server. Negotiation are very
              CPU intensive so an application-specific custom value may prove useful for
              small embedded systems.
              The default is 180 seconds.

              The minimum number of threads in the general threadpool will be
              MONO_THREADS_PER_CPU * number of CPUs. The default value for this
              variable is 1.

              Controls the threshold for the XmlSerializer to produce a custom
              serializer for a given class instead of using the Reflection-based
              interpreter.  The possible values are `no' to disable the use of a
              custom serializer or a number to indicate when the XmlSerializer
              should start serializing.   The default value is 50, which means that
              the a custom serializer will be produced on the 50th use.

              Sets the revocation mode used when validating a X509 certificate chain (https,
              ftps, smtps...).  The default is 'nocheck', which performs no revocation check
              at all. The other possible values are 'offline', which performs CRL check (not
              implemented yet) and 'online' which uses OCSP and CRL to verify the revocation
              status (not implemented yet).

              (Also no_proxy) If both HTTP_PROXY and NO_PROXY are
              set, NO_PROXY will be treated as a comma-separated list of "bypass" domains
              which will not be sent through the proxy. Domains in NO_PROXY may contain
              wildcards, as in "*" or "build????.local". Not supported on
              Windows, Mac OS, iOS or Android.


              If set to any value, temporary source files generated by  ASP.NET  support  classes
              will not be removed. They will be kept in the user's temporary directory.

              If  set,  enables some features of the runtime useful for debugging.  This variable
              should contain a  comma  separated  list  of  debugging  options.   Currently,  the
              following options are supported:

                     Enables small structs alignment to 4/8 bytes.

                     When  this  option is set on ARM, a fallback thread local store will be used
                     instead of the default fast thread local storage primitives.

                     If this variable is set, when the Mono VM runs into a verification  problem,
                     instead  of  throwing an exception it will break into the debugger.  This is
                     useful when debugging verifier problems

              casts  This option can be used to get more detailed  information  from  InvalidCast
                     exceptions, it will provide information about the types involved.

                     This  option  causes  the runtime to check for calling convention mismatches
                     when using pinvoke, i.e. mixing cdecl/stdcall. It only works on windows.  If
                     a mismatch is detected, an ExecutionEngineException is thrown.

                     Collects  information  about  pagefaults.   This is used internally to track
                     the number of page faults  produced  to  load  metadata.   To  display  this
                     information you must use this option with "--stats" command line option.

                     When  this option is set, the runtime will invalidate the domain memory pool
                     instead of destroying it.

                     Disables a compiler optimization where the frame pointer is omitted from the
                     stack. This optimization can interact badly with debuggers.

                     This  is  an  Optimization  for  multi-AppDomain applications (most commonly
                     ASP.NET applications).  Due to internal limitations Mono,  Mono  by  default
                     does not use typed allocations on multi-appDomain applications as they could
                     leak memory when a domain is unloaded.  Although this is a fine default, for
                     applications  that  use more than on AppDomain heavily (for example, ASP.NET
                     applications) it is worth trading off the  small  leaks  for  the  increased
                     performance  (additionally,  since ASP.NET applications are not likely going
                     to unload the application domains on production systems, it is  worth  using
                     this feature).

                     Instructs the runtime to try to use a generic runtime-invoke wrapper instead
                     of creating one invoke wrapper.

                     Makes the JIT generate an  explicit  NULL  check  on  variable  dereferences
                     instead  of  depending on the operating system to raise a SIGSEGV or another
                     form of trap event when an invalid memory location is accessed.

              gdb    Equivalent to setting the MONO_XDEBUG variable, this emits  symbols  into  a
                     shared  library  as the code is JITed that can be loaded into GDB to inspect

                     Automatically generates sequence points where the IL stack is empty.   These
                     are places where the debugger can set a breakpoint.

                     Unless  the  option is used, the runtime generates sequence points data that
                     maps native offsets to IL offsets. Sequence point data is used to display IL
                     offset in stacktraces. Stacktraces with IL offsets can be symbolicated using
                     mono-symbolicate tool.

                     Captures the interrupt signal (Control-C) and displays a  stack  trace  when
                     pressed.   Useful  to  find  out  where  the program is executing at a given
                     point.  This only displays the stack trace of a single thread.

                     Instructs the runtime to initialize the stack with some known  values  (0x2a
                     on x86-64) at the start of a method to assist in debuggin the JIT engine.

                     This  option will leak delegate trampolines that are no longer referenced as
                     to  present  the  user  with  more  information  about  a  delegate  misuse.
                     Basically  a  delegate  instance might be created, passed to unmanaged code,
                     and no references kept in managed code, which will garbage collect the code.
                     With this option it is possible to track down the source of the problems.

                     This  option  will  disable the GDB backtrace emitted by the runtime after a
                     SIGSEGV or SIGABRT in unmanaged code.

                     When this option is set,  the  runtime  can  share  generated  code  between
                     generic types effectively reducing the amount of code generated.

                     This  option will cause mono to abort with a descriptive message when during
                     stack unwinding after an exception it reaches a  native  stack  frame.  This
                     happens  when  a  managed delegate is passed to native code, and the managed
                     delegate throws an exception. Mono will normally try to unwind the stack  to
                     the  first  (managed)  exception  handler, and it will skip any native stack
                     frames in the process. This leads to undefined behaviour (since mono doesn't
                     know how to process native frames), leaks, and possibly crashes too.

                     This   guarantees   that  each  time  managed  code  is  compiled  the  same
                     instructions and registers are used, regardless of the size of used values.

                     This option allows using single-steps and breakpoints in hardware  where  we
                     cannot do it with signals.

                     This  option  will  suspend the program when a native crash occurs (SIGSEGV,
                     SIGILL, ...).  This is useful for debugging  crashes  which  do  not  happen
                     under gdb, since a live process contains more information than a core file.

                     Same as suspend-on-native-crash.

                     This option will suspend the program when an exception occurs.

                     This option will suspend the program when an unhandled exception occurs.

                     Use DIR for storage thread dumps created by SIGQUIT.

                     Don't  enforce  the  CLR  memory model on platforms with weak memory models.
                     This can introduce random crashes in  some  rare  cases,  for  multithreaded
                     environments.  This can be used for a performance boost on applications that
                     are single threaded.

                     Make gdb output on native crashes more verbose.

              The logging level, possible values are `error', `critical',  `warning',  `message',
              `info' and `debug'.  See the DEBUGGING section for more details.

              Controls  the  domain  of the Mono runtime that logging will apply to.  If set, the
              log mask is changed to the set value. Possible values are "asm" (assembly  loader),
              "type", "dll" (native library loader), "gc" (garbage collector), "cfg" (config file
              loader), "aot" (precompiler),  "security"  (e.g.  Moonlight  CoreCLR  support)  and
              "all".   The  default value is "all". Changing the mask value allows you to display
              only messages for a  certain  component.  You  can  use  multiple  masks  by  comma
              separating  them.  For  example  to  see  config  file messages and assembly loader
              messages set you mask to "asm,cfg".

              Controls where trace log messages are written. If not set then the messages  go  to
              stdout.   If  set,  the  string  either  specifies  a path to a file that will have
              messages appended to it, or the string "syslog" in which case the messages will  be
              written  to  the system log.  Under Windows, this is simulated by writing to a file
              called  "mono.log".   MONO_LOG_HEADER  Controls  whether  trace  log  messages  not
              directed  to  syslog  have  the  id,  timestamp,  and  pid as the prefix to the log
              message. To enable a header this environment variable need just be non-null.

              Used for runtime tracing of method calls. The format of the comma  separated  trace
              options is:

                   [-]M:method name
                   [-]T:class name
                   disabled       Trace output off upon start.

              You can toggle trace output on/off sending a SIGUSR2 signal to the program.

              If  set,  enables the System.Diagnostics.DefaultTraceListener, which will print the
              output of the System.Diagnostics Trace and Debug classes.   It  can  be  set  to  a
              filename,  and to Console.Out or Console.Error to display output to standard output
              or standard error, respectively. If it's set to Console.Out  or  Console.Error  you
              can  append  an  optional prefix that will be used when writing messages like this:
              Console.Error:MyProgramName.    See   the   System.Diagnostics.DefaultTraceListener
              documentation for more information.

              This  eases  WCF  diagnostics functionality by simply outputs all log messages from
              WCF engine to "stdout", "stderr" or any file passed to this  environment  variable.
              The log format is the same as usual diagnostic output.

              This  throws  an exception when a X11 error is encountered; by default a message is
              displayed but execution continues

              Set this value to 1 to prevent the serializer from  removing  the  temporary  files
              that are created for fast serialization;  This might be useful when debugging.

              This  is  used in the System.Windows.Forms implementation when running with the X11
              backend.  This is used to debug problems in Windows.Forms as it forces all  of  the
              commands  send  to  X11  server  to  be  done  synchronously.   The default mode of
              operation is asynchronous which makes it  hard  to  isolate  the  root  of  certain

              When  the the MONO_XDEBUG env var is set, debugging info for JITted code is emitted
              into a shared library, loadable into gdb. This enables, for example, to see managed
              frame names on gdb backtraces.

              Enables  the  maximum JIT verbosity for the specified method. This is very helpfull
              to diagnose a miscompilation problems  of  a  specific  method.    This  can  be  a
              semicolon-separated  list  of  method  names to match.  If the name is simple, this
              applies to any method  with  that  name,  otherwise  you  can  use  a  mono  method
              description (see the section METHOD DESCRIPTIONS).

              Enables  sending  of the JITs intermediate representation for a specified method to
              the IdealGraphVisualizer tool.

              If set, makes the JIT output information about detected CPU features (such as  SSE,
              CMOV, FCMOV, etc) to stdout.

              If  set,  the  JIT  will not perform any hardware capability detection. This may be
              useful to pinpoint the cause of JIT issues. This is the default when Mono is  built
              as an AOT cross compiler, so that the generated code will run on most hardware.


       If  you  want  to use Valgrind, you will find the file `mono.supp' useful, it contains the
       suppressions for the GC which trigger incorrect warnings.  Use it like this:
           valgrind --suppressions=mono.supp mono ...


       On some platforms, Mono can expose a  set  of  DTrace  probes  (also  known  as  user-land
       statically defined, USDT Probes).

       They are defined in the file `mono.d'.

       ves-init-begin, ves-init-end
              Begin and end of runtime initialization.

       method-compile-begin, method-compile-end
              Begin  and  end  of method compilation.  The probe arguments are class name, method
              name and signature, and  in  case  of  method-compile-end  success  or  failure  of

       gc-begin, gc-end
              Begin and end of Garbage Collection.

       To verify the availability of the probes, run:
                  dtrace -P mono'$target' -l -c mono


       Mono's  Ping implementation for detecting network reachability can create the ICMP packets
       itself without requiring the system ping command to do the work.  If you  want  to  enable
       this on Linux for non-root users, you need to give the Mono binary special permissions.

       As root, run this command:
          # setcap cap_net_raw=+ep /usr/bin/mono


       On Unix assemblies are loaded from the installation lib directory.  If you set `prefix' to
       /usr, the assemblies will be located in /usr/lib.  On Windows, the assemblies  are  loaded
       from the directory where mono and mint live.

              The  directory  for  the  ahead-of-time  compiler  demand  creation  assemblies are

       /etc/mono/config, ~/.mono/config
              Mono runtime configuration file.  See  the  mono-config(5)  manual  page  for  more

       ~/.config/.mono/certs, /usr/share/.mono/certs
              Contains  Mono  certificate  stores  for users / machine. See the certmgr(1) manual
              page for more information on managing certificate stores and the  mozroots(1)  page
              for  information  on  how  to  import  the  Mozilla root certificates into the Mono
              certificate store.

              Files in this directory allow a user to customize the  configuration  for  a  given
              system assembly, the format is the one described in the mono-config(5) page.

       ~/.config/.mono/keypairs, /usr/share/.mono/keypairs
              Contains  Mono  cryptographic keypairs for users / machine. They can be accessed by
              using    a    CspParameters    object     with     DSACryptoServiceProvider     and
              RSACryptoServiceProvider classes.

       ~/.config/.isolatedstorage, ~/.local/share/.isolatedstorage, /usr/share/.isolatedstorage
              Contains  Mono  isolated  storage  for  non-roaming  users, roaming users and local
              machine.  Isolated  storage  can  be  accessed   using   the   classes   from   the
              System.IO.IsolatedStorage namespace.

              Configuration  information  for individual assemblies is loaded by the runtime from
              side-by-side   files   with   the   .config   files,   see   the   http://www.mono-
     for more information.

       Web.config, web.config
              ASP.NET  applications are configured through these files, the configuration is done
              on  a  per-directory  basis.   For  more  information  on  this  subject  see   the


       Mailing lists are listed at the



       certmgr(1),  cert-sync(1),  csharp(1),  gacutil(1),  mcs(1),  monodis(1),  mono-config(5),
       mono-profilers(1), mprof-report(1), pdb2mdb(1), xsp(1), mod_mono(8)

       For more information on AOT:

       For ASP.NET-related documentation, see the xsp(1) manual page