Provided by: nix-bin_2.16.1+dfsg-3ubuntu1_amd64 bug

Name

       nix-store --add - add paths to Nix store

Synopsis

       nix-store --add paths…

Description

       The  operation  --add  adds  the specified paths to the Nix store. It prints the resulting
       paths in the Nix store on standard output.

Options

       The following options are allowed for all nix-store operations, but may not always have an
       effect.

       • --add-root path

         Causes the result of a realisation (--realise and --force-realise) to be registered as a
         root of the garbage collector. path will be created as a symlink to the resulting  store
         path.   In   addition,   a   uniquely   named   symlink  to  path  will  be  created  in
         /nix/var/nix/gcroots/auto/. For instance,

       $ nix-store --add-root /home/eelco/bla/result --realise ...

       $ ls -l /nix/var/nix/gcroots/auto
       lrwxrwxrwx    1 ... 2005-03-13 21:10 dn54lcypm8f8... -> /home/eelco/bla/result

       $ ls -l /home/eelco/bla/result
       lrwxrwxrwx    1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r11343n6qd4...-f-spot-0.0.10

              Thus, when /home/eelco/bla/result is removed, the GC root  in  the  auto  directory
              becomes a dangling symlink and will be ignored by the collector.

                     Warning

                     Note  that  it is not possible to move or rename GC roots, since the symlink
                     in the auto directory will still point to the old location.

              If  there  are  multiple  results,  then  multiple  symlinks  will  be  created  by
              sequentially  numbering symlinks beyond the first one (e.g., foo, foo-2, foo-3, and
              so on).

Common Options

       Most Nix commands accept the following command-line options:

       • --help
         Prints out a summary of the command syntax and exits.

       • --version
         Prints out the Nix version number on standard output and exits.

       • --verbose / -v
         Increases the level of verbosity of diagnostic messages printed on standard  error.  For
         each  Nix  operation,  the  information  printed on standard output is well-defined; any
         diagnostic information is printed on standard error, never on standard output.

         This option may be specified  repeatedly.  Currently,  the  following  verbosity  levels
         exist:

         • 0
           “Errors only”: only print messages explaining why the Nix invocation failed.

         • 1
           “Informational”: print useful messages about what Nix is doing. This is the default.

         • 2
           “Talkative”: print more informational messages.

         • 3
           “Chatty”: print even more informational messages.

         • 4
           “Debug”: print debug information.

         • 5
           “Vomit”: print vast amounts of debug information.

       • --quiet
         Decreases  the level of verbosity of diagnostic messages printed on standard error. This
         is the inverse option to -v / --verbose.

         This option may be specified repeatedly. See the previous verbosity levels list.

       • --log-format format
         This option can be used to change the output of the log format, with  format  being  one
         of:

         • raw
           This is the raw format, as outputted by nix-build.

         • internal-json
           Outputs the logs in a structured manner.

                  Warning

                  While  the schema itself is relatively stable, the format of the error-messages
                  (namely of the msg-field) can change between releases.

         • bar
           Only display a progress bar during the builds.

         • bar-with-logs
           Display the raw logs, with the progress bar at the bottom.

       • --no-build-output / -Q
         By default, output written by builders to standard output and standard error  is  echoed
         to  the  Nix  command’s standard error. This option suppresses this behaviour. Note that
         the  builder’s  standard  output  and  error  are  always  written  to  a  log  file  in
         prefix/nix/var/log/nix.

       • --max-jobs / -j number
         Sets the maximum number of build jobs that Nix will perform in parallel to the specified
         number. Specify auto to use the number of CPUs in the system. The default  is  specified
         by  the  max-jobs  configuration  setting, which itself defaults to 1. A higher value is
         useful on SMP systems or to exploit I/O latency.

         Setting it to 0 disallows building on the local machine, which is useful when  you  want
         builds to happen only on remote builders.

       • --cores
         Sets  the  value  of  the  NIX_BUILD_CORES  environment  variable  in  the invocation of
         builders. Builders can use this variable at their  discretion  to  control  the  maximum
         amount   of   parallelism.  For  instance,  in  Nixpkgs,  if  the  derivation  attribute
         enableParallelBuilding is set to true, the builder passes the -jN flag to GNU  Make.  It
         defaults  to  the  value of the cores configuration setting, if set, or 1 otherwise. The
         value 0 means that the builder should use all available CPU cores in the system.

       • --max-silent-time
         Sets the maximum number of seconds that a builder can go without producing any  data  on
         standard  output  or  standard  error.  The  default is specified by the max-silent-time
         configuration setting. 0 means no time-out.

       • --timeout
         Sets the maximum number of seconds that a builder can run. The default is  specified  by
         the timeout configuration setting. 0 means no timeout.

       • --keep-going / -k
         Keep  going  in  case  of  failed  builds,  to the greatest extent possible. That is, if
         building an input of some derivation fails, Nix will still build the other  inputs,  but
         not the derivation itself. Without this option, Nix stops if any build fails (except for
         builds of substitutes), possibly killing builds in progress  (in  case  of  parallel  or
         distributed builds).

       • --keep-failed / -K
         Specifies  that in case of a build failure, the temporary directory (usually in /tmp) in
         which the build takes place should not be deleted. The path of the  build  directory  is
         printed as an informational message.

       • --fallback
         Whenever  Nix  attempts  to  build a derivation for which substitutes are known for each
         output path, but realising the output paths through the substitutes fails, fall back  on
         building the derivation.

         The  most common scenario in which this is useful is when we have registered substitutes
         in order to perform  binary  distribution  from,  say,  a  network  repository.  If  the
         repository  is  down,  the  realisation of the derivation will fail. When this option is
         specified, Nix will build the derivation instead. Thus, installation from binaries falls
         back  on  installation from source. This option is not the default since it is generally
         not desirable for a transient failure in obtaining the substitutes to  lead  to  a  full
         build from source (with the related consumption of resources).

       • --readonly-mode
         When  this  option  is  used,  no  attempt  is  made  to open the Nix database. Most Nix
         operations do need database access, so those operations will fail.

       • --arg name value
         This option is accepted by  nix-env,  nix-instantiate,  nix-shell  and  nix-build.  When
         evaluating  Nix  expressions,  the  expression  evaluator will automatically try to call
         functions that it encounters. It  can  automatically  call  functions  for  which  every
         argument  has  a default value (e.g., { argName ?  defaultValue }: ...). With --arg, you
         can also call functions that have arguments without  a  default  value  (or  override  a
         default  value).  That is, if the evaluator encounters a function with an argument named
         name, it will call it with value value.

         For instance, the top-level default.nix in Nixpkgs is actually a function:

       { # The system (e.g., `i686-linux') for which to build the packages.
         system ? builtins.currentSystem
         ...
       }: ...

              So if you call this Nix expression (e.g., when  you  do  nix-env  --install  --attr
              pkgname),   the   function   will   be   called   automatically   using  the  value
              builtins.currentSystem for the system argument. You can override this using  --arg,
              e.g.,  nix-env  --install  --attr pkgname --arg system \"i686-freebsd\". (Note that
              since the argument is a Nix string literal, you have to escape the quotes.)

       • --argstr name value
         This option is like --arg, only the value is not a  Nix  expression  but  a  string.  So
         instead  of  --arg  system \"i686-linux\" (the outer quotes are to keep the shell happy)
         you can say --argstr system i686-linux.

       • --attr / -A attrPath
         Select an attribute from the top-level Nix expression being  evaluated.  (nix-env,  nix-
         instantiate, nix-build and nix-shell only.) The attribute path attrPath is a sequence of
         attribute names separated by dots. For instance, given a top-level Nix expression e, the
         attribute  path xorg.xorgserver would cause the expression e.xorg.xorgserver to be used.
         See nix-env --install for some concrete examples.

         In addition to attribute names, you can also specify array indices.  For  instance,  the
         attribute path foo.3.bar selects the bar attribute of the fourth element of the array in
         the foo attribute of the top-level expression.

       • --expr / -E
         Interpret the command line arguments as a list of  Nix  expressions  to  be  parsed  and
         evaluated,  rather  than  as  a list of file names of Nix expressions. (nix-instantiate,
         nix-build and nix-shell only.)

         For nix-shell, this option is commonly used to give you a shell in which you  can  build
         the  packages  returned  by the expression. If you want to get a shell which contain the
         built packages  ready  for  use,  give  your  expression  to  the  nix-shell  --packages
         convenience flag instead.

       • -I path
         Add  an  entry  to  the  Nix  expression search path.  This option may be given multiple
         times.  Paths added through -I take precedence over NIX_PATH.

       • --option name value
         Set the Nix configuration option name to value.  This  overrides  settings  in  the  Nix
         configuration file (see nix.conf5).

       • --repair
         Fix corrupted or missing store paths by redownloading or rebuilding them. Note that this
         is slow because it requires computing a cryptographic hash of the contents of every path
         in the closure of the build. Also note the warning under nix-store --repair-path.

Common Environment Variables

       Most Nix commands interpret the following environment variables:

       • IN_NIX_SHELL
         Indicator that tells if the current environment was set up by nix-shell. It can have the
         values pure or impure.

       • NIX_PATH
         A colon-separated list of directories used to look up the location  of  Nix  expressions
         using  paths enclosed in angle brackets (i.e., <path>), e.g. /home/eelco/Dev:/etc/nixos.
         It can be extended using the -I option.

         If NIX_PATH is not set at all, Nix will fall back to the following list  in  impure  and
         unrestricted evaluation mode:

         1.     $HOME/.nix-defexpr/channels
         2.     nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixpkgs
         3.     /nix/var/nix/profiles/per-user/root/channels

         If  NIX_PATH  is  set  to an empty string, resolving search paths will always fail.  For
         example, attempting to use <nixpkgs> will produce:

       error: file 'nixpkgs' was not found in the Nix search path

       • NIX_IGNORE_SYMLINK_STORE
         Normally, the Nix store directory (typically /nix/store) is not allowed to  contain  any
         symlink   components.   This   is   to   prevent  “impure”  builds.  Builders  sometimes
         “canonicalise” paths by resolving all symlink  components.  Thus,  builds  on  different
         machines  (with  /nix/store  resolving  to  different  locations)  could yield different
         results. This is generally not a problem, except when builds are  deployed  to  machines
         where /nix/store resolves differently. If you are sure that you’re not going to do that,
         you can set NIX_IGNORE_SYMLINK_STORE to 1.

         Note that if you’re symlinking the Nix store so that you can  put  it  on  another  file
         system  than  the  root file system, on Linux you’re better off using bind mount points,
         e.g.,

       $ mkdir /nix
       $ mount -o bind /mnt/otherdisk/nix /nix

              Consult the mount 8 manual page for details.

       • NIX_STORE_DIR
         Overrides the location of the Nix store (default prefix/store).

       • NIX_DATA_DIR
         Overrides the location of the Nix static data directory (default prefix/share).

       • NIX_LOG_DIR
         Overrides the location of the Nix log directory (default prefix/var/log/nix).

       • NIX_STATE_DIR
         Overrides the location of the Nix state directory (default prefix/var/nix).

       • NIX_CONF_DIR
         Overrides  the  location  of   the   system   Nix   configuration   directory   (default
         prefix/etc/nix).

       • NIX_CONFIG
         Applies settings from Nix configuration from the environment.  The content is treated as
         if it was read from a Nix configuration file.  Settings are  separated  by  the  newline
         character.

       • NIX_USER_CONF_FILES
         Overrides the location of the Nix user configuration files to load from.

         The  default  are  the locations according to the XDG Base Directory Specification.  See
         the XDG Base Directories sub-section for details.

         The variable is treated as a list separated by the : token.

       • TMPDIR
         Use the specified directory to store  temporary  files.  In  particular,  this  includes
         temporary  build  directories;  these can take up substantial amounts of disk space. The
         default is /tmp.

       • NIX_REMOTE
         This variable should be set to daemon if you want to use the Nix daemon to  execute  Nix
         operations.  This is necessary in multi-user Nix installations. If the Nix daemon’s Unix
         socket  is   at   some   non-standard   path,   this   variable   should   be   set   to
         unix://path/to/socket. Otherwise, it should be left unset.

       • NIX_SHOW_STATS
         If  set  to  1,  Nix will print some evaluation statistics, such as the number of values
         allocated.

       • NIX_COUNT_CALLS
         If set to 1, Nix will print how  often  functions  were  called  during  Nix  expression
         evaluation. This is useful for profiling your Nix expressions.

       • GC_INITIAL_HEAP_SIZE
         If  Nix  has  been configured to use the Boehm garbage collector, this variable sets the
         initial size of the heap in bytes. It defaults to 384 MiB. Setting it  to  a  low  value
         reduces  memory  consumption,  but  will increase runtime due to the overhead of garbage
         collection.

   XDG Base Directories
       Nix follows the XDG Base Directory Specification.

       For backwards compatibility, Nix commands will follow the standard only when use-xdg-base-
       directories  is  enabled.   New  Nix  commands  (experimental)  conform to the standard by
       default.

       The following environment variables are used to determine locations of various  state  and
       configuration files:

       • [XDG_CONFIG_HOME]{#env-XDGCONFIGHOME} (default ~/.config)
       • [XDG_STATE_HOME]{#env-XDGSTATEHOME} (default ~/.local/state)
       • [XDG_CACHE_HOME]{#env-XDGCACHEHOME} (default ~/.cache)

Example

       $ nix-store --add ./foo.c
       /nix/store/m7lrha58ph6rcnv109yzx1nk1cj7k7zf-foo.c

                                                                                nix-store –add(1)