Provided by: ocaml-findlib_1.5.5-2build1_amd64 bug

NAME

       ocamlfind - [Command-line interface of the Package manager]

SYNOPSIS

              ocamlfind query [-help | other options] package_name ...
          or: ocamlfind ocamlc [-help | other options] file ...
          or: ocamlfind ocamlcp [-help | other options] file ...
          or: ocamlfind ocamlmktop [-help | other options] file ...
          or: ocamlfind ocamlopt [-help | other options] file ...
          or: ocamlfind ocamldoc [-help | other options] file ...
          or: ocamlfind ocamldep [-help | other options] file ...
          or: ocamlfind ocamlmklib [-help | other options] file ...
          or: ocamlfind ocamlbrowser [-help | other options]
          or: ocamlfind install [-help | other options] package_name file ...
          or: ocamlfind remove [-help | other options] package_name
          or: ocamlfind list [-describe]
          or: ocamlfind printconf [ variable ]
          or: ocamlfind package/command arg ...

       Optional toolchain selection by:
         ocamlfind -toolchain name ...

THE 'query' SUBCOMMAND

   Synopsis
       ocamlfind query [ -predicates p  |
                         -format f |
                         -long-format | -l |
                         -i-format |
                         -l-format |
                         -a-format |
                         -o-format |
                         -p-format |
                         -prefix p |
                         -separator s |
                         -suffix s |
                         -pp |
                         -descendants | -d |
                         -recursive  | -r ] package ...

   Description
       This  command  looks packages up, sorts them optionally, and prints attributes of them. If
       the option -recursive (short: -r) is not specified, exactly  the  packages  given  on  the
       command  line  are  looked  up;  if  -recursive  is  present,  the  packages and all their
       ancestors, or if -descendants (short: -d) is  present,  too,  all  their  descendants  are
       printed.

       Package  lookup  and  the  selection  of the attributes of the packages can be modified by
       specifying predicates; without a -predicates option the empty set of predicates  is  used.
       Note  that even the lookup is influenced by the set of actual predicates as the "requires"
       variables may be conditional.

       What is printed about a package depends on the specified format; there  are  a  number  of
       options  that  modify the format. Some formats denote sets of values (such as -format %a),
       in which case multiple output records are printed for every package. (It is even  possible
       to  specify formats denoting the Cartesian product of sets, such as -format %a%o, but this
       does not make sense.) Before the first output record the prefix is printed, and the suffix
       after the last record. Between two records the separator is printed.

   Options
         -predicates p

              Sets  the  set  of  actual predicates. The argument  p is a list of predicate names
              separated  by commas and/or whitespace. If multiple -predicates options are  given,
              the union of all specified sets is effectively used.

         -format f

              Sets  the  format  to  the  string    f. Characters preceded by a percent sign  are
              interpreted as placeholders; all other characters mean    themselves.  The  defined
              placeholders are listed below.  The default format is "%d".

         -long-format or -l

              Sets the format such that all relevant variables are printed.

         -i-format

              Same as -format "-I %d", i.e. directory options for ocamlc are printed.

         -l-format

              Same  as  -format  "-ccopt -L%d", i.e. directory options for the linker backend are
              printed.

         -a-format

              Same as -format "%+a", i.e. archive file names are printed.

         -o-format

              Same as -format "%o", i.e. linker options are printed.

         -p-format

              Same as -format "%p", i.e. package names are printed.

         -prefix p

              Sets the prefix that is printed before the  first  output  record    to  the  given
              string. The default prefix is the empty string.

         -suffix s

              Sets  the suffix that is printed after the last output record  to the given string.
              The default suffix is the empty string.

         -separator s

              Sets the separator that is printed between output records to  the given string. The
              default separator is a linefeed character.

         -recursive or -r

              Not only the packages given on the command line are queried  but also all ancestors
              or descendants. If the option -descendants is  specified, too, the descendants  are
              printed, otherwise the  ancestors. The packages are topologically sorted.

         -descendants -d

              Instead  of  the ancestors the descendants of the  given packages are queried. This
              option implies -recursive.

         -pp

              Query preprocessor packages (camlp4 syntax extensions). Normally it is  not  needed
              to  set -predicates, except you need the archives (then add -predicates byte). This
              option implies -recursive.

   Placeholders meaningful in the -format option
         %%

              Replaced by a single percent sign

         %p

              Replaced by the package name

         %d

              Replaced by the package directory

         %D

              Replaced by the package description

         %v

              Replaced by the version string

         %a

              Replaced by the archive filename. If there is more  than one  archive,  a  separate
              output record is printed for every archive.

         %+a

              Like  %a, but the filenames are converted to absolute  paths ("+" and "@" notations
              are resolved)

         %A

              Replaced by the list of archive filenames.

         %+A

              Like %A, but the filenames are converted to absolute  paths ("+" and "@"  notations
              are resolved)

         %o

              Replaced by one linker option. If there is more than  one option, a separate output
              record is printed for every option.

         %O

              Replaced by the list of linker options.

         %(property)

              Replaced by the value of the property named in parentheses, or the empty string  if
              not defined.

THE SUBCOMMANDS 'ocamlc', 'ocamlcp', 'ocamlopt', and 'ocamlmktop'

   Synopsis
       ocamlfind ( ocamlc | ocamlcp | ocamlopt | ocamlmktop )
                 [ -package package-name-list |
                   -linkpkg |
                   -predicates pred-name-list |
                   -dontlink package-name-list |
                   -syntax pred-name-list |
                   -ppopt camlp4-arg |
                   -ppxopt package,arg |
                   -dllpath-pkg package-name-list |
                   -dllpath-all |
                   -passopt arg |
                   -passrest arg... |
                   -only-show |
                   standard-option ]
                 file ...

   Description
       These  subcommands  are  drivers  for  the  compilers with the same names, i.e. "ocamlfind
       ocamlc" is a driver for "ocamlc", and so on. The  subcommands  understand  all  documented
       options  of  the compilers (here called standard-options), but also a few more options. If
       these subcommands are invoked only with standard options, they behave as if the underlying
       compiler had been called directly. The extra options modify this.

       Internally,  these subcommands transform the given list of options and file arguments into
       an invocation of the driven compiler. This transformation only adds options and files, and
       the relative order of the options and files passed directly is unchanged.

       If  there  are  -package  options, additional directory search specifiers will be included
       ("-I", and "-ccopt -I"), such that files of all named packages and all  ancestors  can  be
       found.

       The  -linkpkg  option  causes  that  the  packages  listed in the -package options and all
       necessary ancestors are linked in. This means that  the  archive  files  implementing  the
       packages are inserted into the list of file arguments.

       As  the package database is queried a set of predicates is needed. Most predicates are set
       automatically, see below, but additional predicates can be given by a -predicates option.

       If there is a -syntax option, the drivers assume that a preprocessor is  to  be  used.  In
       this  case,  the  preprocessor  command  is  built first in a preprocessor stage, and this
       command is passed to the compiler using the -pp option.  The  set  of  predicates  in  the
       preprocessor stage is different from the set in the compiler/linker stage.

   Options for compiling and linking
       Here,  only  the  additional  options  not  interpreted  by the compiler but by the driver
       itself, and  options  with  additional  effects  are  explained.  Some  options  are  only
       meaningful for the preprocessor call, and are explained below.

         -package package-name-list

              Adds  the  listed package names to the set of included  packages. The package names
              may be separated by commas and/or  whitespace.  In  the  transformed  command,  for
              every  package  of  the  set  of included packages and for any ancestor a directory
              search option  is inserted after the already given options. This means that    "-I"
              and "-ccopt -I" options are added for every package directory.

         -linkpkg

              Causes  that  in the transformed command all archives  of the packages specified by
              -packages and all their ancestors are  added to the file arguments. More precisely,
              these  archives  are    inserted before the first given file argument. Furthermore,
              "-ccopt  -L" options for all package directories, and the linker options  of    the
              selected  packages  are  added,  too.  Note  that  the  archives  are   inserted in
              topological order while the linker options are added in  reverse toplogical order.

         -predicates pred-name-list

              Adds the given predicates to the set of actual  predicates. The predicates must  be
              separated by commas and/or  whitespace.

         -dontlink package-name-list

              This  option  modifies  the behaviour of  -linkpkg. Packages specified here and all
              ancestors are not linked  in. Again the packages are  separated  by  commas  and/or
              whitespace.

         -dllpath-pkg package-name-list

              For these packages -dllpath options  are added to the compiler command. This may be
              useful when the ld.conf  file is not properly configured.

         -dllpath-all

              For all linked packages -dllpath options  are added to the compiler  command.  This
              may be useful when the ld.conf  file is not properly configured.

         -passopt arg

              The argument arg is  passed directly to the underlying compiler. This is needed to
              specify undocumented compiler options.

         -passrest arg...

              All following arguments arg... are  passed directly  to  the  underlying  compiler.
              This is needed to  specify undocumented compiler options.

         -only-show

              Only  prints  the  constructed  command  (ocamlc/ocamlopt) to  stdout, but does not
              execute the command. (This is for the unlikely event    that  you  need  a  wrapper
              around ocamlfind.)

         -verbose

              This standard option is interpreted by the driver, too.

         -thread

              This  standard option causes that the predicate "mt"  is added to the set of actual
              predicates. If POSIX threads are available,  the predicate "mt_posix" is  selected,
              too.  If only VM threads are  available, the predicate "mt_vm" is included into the
              set, and the  compiler switch is changed into -vmthread.

              Note that the presence  of  the  "mt"  predicate  triggers  special  fixup  of  the
              dependency graph (see below).

         -vmthread

              This  standard option causes that the predicates "mt"  and "mt_vm" are added to the
              set of actual predicates.

              Note that the presence  of  the  "mt"  predicate  triggers  special  fixup  of  the
              dependency graph (see below).

         -p

              This  standard  option of "ocamlopt" causes that the  predicate "gprof" is added to
              the set of actual predicates.

   Options for preprocessing
       The options relevant for the preprocessor are the following:

         -package package-name-list

              These packages are considered while looking up the    preprocessor  arguments.  (It
              does  not  cause  problems that the same  -package option is used for this purpose,
              because the set of predicates  is different.) It is recommended to mention at least
              camlp4  here if the preprocessor is going to be used.

         -syntax pred-name-list

              These  predicates  are assumed to be true in addition  to the standard preprocessor
              predicates. See below for a list.

         -ppopt camlp4-arg

              This argument is passed to the camlp4 call.

   Predicates for compiling and linking
         byte

              The "byte" predicate means that one of  the  bytecode  compilers  is  used.  It  is
              automatically  included  into  the  predicate  set  if  the "ocamlc", "ocamlcp", or
              "ocamlmktop" compiler is used.

         native

              The "native" predicate means that the native compiler is used. It is  automatically
              included into the predicate set if the "ocamlopt" compiler is used.

         toploop

              The  "toploop" predicate means that the toploop is available in the linked program.
              This predicate is only set when the toploop is actually being  executed,  not  when
              the toploop is created (this changed in version 1.0.4 of findlib).

         create_toploop

              This predicate means that a toploop is being created (using ocamlmktop).

         mt

              The  "mt"  predicate  means that the program is multi-threaded. It is automatically
              included into the predicate set if the -thread option is given.

         mt_posix

              The "mt_posix" predicate means that in  the  case  "mt"  is  set,  too,  the  POSIX
              libraries  are used to implement threads. "mt_posix" is automatically included into
              the predicate set if the variable "type_of_threads" in the META description of  the
              "threads"  package has the value "posix". This is normally the case if "findlib" is
              configured for POSIX threads.

         mt_vm

              The "mt_vm" predicate means that in the case  "mt"  is  set,  too,  the  VM  thread
              emulation is used to implement multi-threading.

         gprof

              The  "gprof"  predicate means that in the case "native" is set, too, the program is
              compiled for profiling. It is automatically included  into  the  predicate  set  if
              "ocamlopt" is used and the -p option is in effect.

         autolink

              The "autolink" predicate means that ocamlc is able to perform automatic linking. It
              is automatically included into the predicate set if ocamlc knows automatic  linking
              (from version 3.00), but it is not set if the -noautolink option is set.

         syntax

              This  predicate  is  set  if  there  is  a  -syntax  option. It is set both for the
              preprocessor and the compiler/linker stage,  and it can be used to find out whether
              the preprocessor is enabled or not.

   Predicates for preprocessing
         preprocessor

              This  predicate  is always set while looking up the  preprocessor arguments. It can
              be used to distinguish between the   preprocessor  stage  and  the  compiler/linker
              stage.

         syntax

              This  predicate  is  set  if  there  is  a  -syntax  option. It is set both for the
              preprocessor and the compiler/linker stage,  and it can be used to find out whether
              the preprocessor is enabled or not.

         camlp4o

              This  is  the reserved predicate for the standard O'Caml syntax.  It can be used in
              the -syntax predicate list.

         camlp4r

              This is the reserved predicate for the revised O'Caml syntax.  It can  be  used  in
              the -syntax predicate list.

   Special behaviour of 'ocamlmktop'
       As  there  is  a  special module Topfind that supports loading of packages in scripts, the
       "ocamlmktop" subcommand can add initialization code for this module. This  extra  code  is
       linked into the executable if "findlib" is in the set of effectively linked packages.

   Fixup of the dependency graph for multi-threading
       For  a  number of reasons the presence of the "mt" predicate triggers that (1) the package
       "threads" is added to the list of required packages and (2) the package "threads"  becomes
       prerequisite  of all other packages (except of itself and a few hardcoded exceptions). The
       effect is that the options  -thread  and  -vmthread  automatically  select  the  "threads"
       package, and that "threads" is inserted at the right position in the package list.

   Extended file naming
       At  a number of places one can not only refer to files by absolute or relative path names,
       but also by extended names. These have two major forms: "+name" refers to the subdirectory
       name of the standard library directory, and "@name" refers to the package directory of the
       package name. Both forms can be continued by a path, e.g. "@netstring/netstring_top.cma".

       You can use extended names: (1) With -I options, (2)  as  normal  file  arguments  of  the
       compiler, (3) in the  "archive" property of packages.

   How to set the names of the compiler executables
       Normally,  the O'Caml bytecode compiler can be called under the name ocamlc. However, this
       is not always true; sometimes a different name is chosen.

       You can instruct ocamlfind to call executables with other  names  than  ocamlc,  ocamlopt,
       ocamlmktop,  and  ocamlcp.  If  present,  the  environment  variable OCAMLFIND_COMMANDS is
       interpreted as a mapping from the standard names to the actual names of  the  executables.
       It must have the following format:

       standardname1=actualname1 standardname2=actualname2 ...

       Example: You may set OCAMLFIND_COMMANDS as follows:

       OCAMLFIND_COMMANDS='ocamlc=ocamlc-3.00 ocamlopt=ocamlopt-3.00'
       export OCAMLFIND_COMMANDS

       Alternatively, you can change the configuration file findlib.conf.

THE SUBCOMMAND 'ocamlmklib'

   Synopsis
       ocamlfind ocamlmklib
                 [ -package package-name-list |
                   -predicates pred-name-list |
                   -dllpath-pkg package-name-list |
                   -dllpath-all |
                   -passopt arg |
                   -passrest arg... |
                   standard-option ]
                   file ...

   Description
       This is a wrapper around ocamlmklib, and creates library archives and DLLs. In addition to
       the standard options, one can use -package to add the search path of packages.  Note  that
       no predicates are set by default - the wrapper does not know whether this is about byte or
       native code linking.

       This wrapper is mostly provided for completeness.

THE 'ocamldep' SUBCOMMAND

   Synopsis
       ocamlfind ocamldep [-package package-name-list |
                           -syntax pred-name-list |
                           -ppopt camlp4-arg |
                           -passopt arg |
                           -passrest arg... |
                           -verbose |
                           standard-option] file ...

   Description
       This command is a driver for the tool ocamldep of the O'Caml distribution. This driver  is
       only  useful  in  conjunction  with the preprocessor camlp4; otherwise it does not provide
       more functions than ocamldep itself.

   Options
       Here, only the additional options not interpreted by ocamldep but by  the  driver  itself,
       and options with additional effects are explained.

         -package package-name-list

              The  packages  named  here  are  only used to look up the preprocessor options. The
              package  camlp4  should  be  specified  anyway,  but  further  packages  that   add
              capabilities to the preprocessor can also be passed.

         -syntax pred-name-list

              The  predicates  that are in effect during the look-up of the preprocessor options.
              At least, either camlp4o (selecting the normal syntax), or camlp4r  (selecting  the
              revised syntax) should be specified.

         -ppopt camlp4-arg

              An option that is passed through to the camlp4 call.

         -passopt arg

              An option that is passed through to the ocamldep call.

         -passrest arg...

              All further arguments are passed down to ocamldep  unprocessed

         -verbose

              Displays the resulting ocamldep command (for debugging)

   Example
       A typical way of using this driver:

       ocamlfind ocamldep -package camlp4,xstrp4 -syntax camlp4r file1.ml file2.ml
           This command outputs the dependencies of file1.ml and file2.ml, although these modules
       make use of the syntax extensions provided by xstrp4 and are written in revised syntax.

THE 'ocamlbrowser' SUBCOMMAND

   Synopsis
       ocamlfind ocamlbrowser [-package package-name-list |
                               -all |
                               -passopt arg
                               -passrest ]

   Description
       This driver calls the ocamlbrowser with package  options.  With  -package,  the  specified
       packages  are  included  into  the  search  path  of the browser, and the modules of these
       packages become visible (in addition to the standard library). The option -all causes that
       all packages are selected that are managed by findlib.

       As  for  other  drivers,  the options -passopt and -passrest can be used to pass arguments
       directly to the ocamlbrowser program.

THE SUBCOMMAND 'ocamldoc'

   Synopsis
       ocamlfind ocamldoc
                 [ -package package-name-list |
                   -predicates pred-name-list |
                   -syntax pred-name-list |
                   -ppopt camlp4-arg |
                   standard-option ]
                 file ...

   Description
       This subcommand is a driver for ocamldoc. It undestands all options ocamldoc supports plus
       the  mentioned  findlib  options.  Basically,  the -package options are translated into -I
       options, and the selected syntax options are translated into camlp4 options.

   Options
       Here, only the additional options not interpreted by ocamldep but by  the  driver  itself,
       and options with additional effects are explained.

         -package package-name-list

              Adds  the  listed package names to the set of included  packages. The package names
              may be separated by commas and/or  whitespace.  In  the  transformed  command,  for
              every  package  of  the  set  of included packages and for any ancestor a directory
              search option  is inserted after the already given options. This means that    "-I"
              options are added for every package directory.

         -predicates pred-name-list

              Adds  the given predicates to the set of actual  predicates. The predicates must be
              separated by commas and/or  whitespace.

         -syntax pred-name-list

              The predicates that are in effect during the look-up of the  preprocessor  options.
              At  least,  either camlp4o (selecting the normal syntax), or camlp4r (selecting the
              revised syntax) should be specified.

         -ppopt camlp4-arg

              An option that is passed through to the camlp4 call.

THE 'install' SUBCOMMAND

   Synopsis
       ocamlfind install [ -destdir directory ]
                         [ -metadir directory ]
                         [ -ldconf path ]
                         [ -dont-add-directory-directive ]
                         [ -patch-version string ]
                         [ -patch-rmpkg name ]
                         [ -patch-archives ]
                         [ -dll ] [ -nodll ] [ -optional ] [ -add ]
                         package_name file ...

   Description
       This subcommand installs a new package either at the default location  (see  the  variable
       destdir of findlib.conf), or in the directory specified by the -destdir option. This means
       that a new package directory is created and that the files on the command line are  copied
       to  this  directory.  It  is  required  that a META file is one of the files copied to the
       target directory.

       Note that package directories should be flat (no subdirectories).  Existing  packages  are
       never overwritten.

       It  is possible to have a separate directory for all the META files. If you want that, you
       have either to set the variable metadir of   findlib.conf,  or  to  specify  the  -metadir
       option.  In  this  case,  the  file  called  META is copied to the specified directory and
       renamed to META.p (where p is the package name), while all the other files are  copied  to
       the  package  directory  as  usual.  Furthermore,  the META file is modified such that the
       directory variable contains the path of the package directory.

       The option -dont-add-directory-directive prevents the installer from  adding  a  directory
       variable.

       If there are files ending in the suffixes .so or .dll, the package directory will be added
       to the DLL configuration file ld.conf, such that the dynamic loader can find the DLL.  The
       location  of  this  file can be overriden by the -ldconf option. To turn this feature off,
       use "-ldconf ignore"; this causes that the ld.conf file is not modified.

       However, if there is a stublibs directory in site-lib, the DLLs are not installed  in  the
       package directory, but in this directory that is shared by all packages that are installed
       at the same location. In this case, the configuration file ld.conf is not modified, so you
       do not need to say "-ldconf ignore" if you prefer this style of installation.

       The  options  -dll and -nodll can be used to control exactly which files are considered as
       DLLs and which not. By default, the mentioned suffix rule is in effect:  files  ending  in
       ".so" (Unix) or ".dll" (Windows) are DLLs. The switch -dll changes this, and all following
       files are considered as DLLs, regardless of their suffix. The  switch    -nodll  expresses
       that  the  following files are not DLLs, even if they have a DLL-like suffix. For example,
       in the following call the files f1 and f2 are handled by the suffix rule; f3  and  f4  are
       DLLs anyway; and f5 and f6 are not DLLs:

       ocamlfind install p f1 f2 -dll f3 f4 -nodll f5 f6

       The switch -optional declares that all following files are optional, i.e. the command will
       not fail if files do not exist.

       The -patch options may be used to change the contents of the META files while it is  being
       installed.  The  option  -patch-version  changes  the  contents of the top-level "version"
       variable. The option -patch-rmpkg removes the given subpackage. The option -patch-archives
       is experimental, in particular it removes all non-existing files from "archive" variables,
       and even whole subpackages if the archives are missing.

       The effect of -add is to add further files to an already installed packages.

THE 'remove' SUBCOMMAND

   Synopsis
       ocamlfind remove [ -destdir directory ]
                        [ -metadir directory ]
                        [ -ldconf path ]
                        package_name

   Description
       The package will removed if it is installed at the default location    (see  the  variable
       destdir  of  findlib.conf). If the package resides at a different location, it will not be
       removed by default; however, you can pass an  alternate  directory  for  packages  by  the
       -destdir option. (This must be the same directory as specified at installation time.)

       Note  that  package directories should be flat (no subdirectories); this subcommand cannot
       remove deep package directories.

       If you have a separate directory for META files, you must either configure this  directory
       by the metadir variable of findlib.conf, or by specifying the -metadir option.

       The  command does not fail if the package and/or the META file cannot be located. You will
       get a warning only in this case.

       If the package directory is mentioned in the ld.conf configuration file for DLLs, it  will
       be tried to remove this entry from the file. The location of this file can be overriden by
       the -ldconf option. To turn this feature off, use "-ldconf ignore"; this causes  that  the
       ld.conf file is not modified.

       If  there is a stublibs directory, it is checked whether the package owns any of the files
       in this directory, and the owned files will be deleted.

THE 'list' SUBCOMMAND

   Synopsis
       ocamlfind list [-describe]

   Description
       This command lists all packages in the search  path.  The  option  -describe  outputs  the
       package descriptions, too.

THE 'printconf' SUBCOMMAND

   Synopsis
       ocamlfind printconf [ conf | path | destdir | metadir | stdlib | ldconf ]

   Description
       This  command prints the effective configuration after reading the configuration file, and
       after applying the various environment variables overriding settings. When called  without
       arguments,  the  command  prints  all configuration options in a human-readable form. When
       called with an argument, only the  value  of  the  requested  option  is  printed  without
       explaining texts:

         conf

              Prints the location of the configuration file findlib.conf

         path

              Prints  the  search  path  for  packages. The members of the  path are separated by
              linefeeds.

         destdir

              Prints the location where package are installed and  removed by default.

         metadir

              Prints the location where META files are installed and  removed (if the alternative
              layout is used).

         stdlib

              Prints the location of the standard library.

         ldconf

              Prints the location of the ld.conf file

THE SUBCOMMAND CALLING PACKAGE PROGRAMS

   Synopsis
       ocamlfind pkg/cmd argument ...

   Description
       This  subcommand  is useful to call programs that are installed in package directories. It
       looks up the directory for  pkg and calls the command named cmd  in  this  directory.  The
       remaining arguments are passed to this command.

       argv(0)  contains  the  absolute  path  to the command, and argv(1) and the following argv
       entries contain the arguments. The working directory is not changed.

       Example: To call the program "x" that is installed in package "p", with arguments "y"  and
       "z", run:

       ocamlfind p/x y z

CONFIGURATION FILE, ENVIRONMENT VARIABLES

       The  configuration  file  and environment variables are documented in the manual page for
       findlib.conf.

HOW TO SET THE TOOLCHAIN

   Synopsis
       ocamlfind -toolchain name ...

   Description
       The -toolchain option can be given before any other command, e.g.

       ocamlfind -toolchain foo ocamlc -c file.ml
        compiles file.ml with  toolchain  "foo".  By  selecting  toolchains  one  can  switch  to
       different  command sets. For instance, the toolchain "foo" may consist of a patched ocamlc
       compiler.   See findlib.conf how to configure toolchains.