nix-env --upgrade(1)

Name

nix-env --upgrade - upgrade packages in user environment

Synopsis

nix-env {--upgrade | -u} args [--lt | --leq | --eq | --always] [{--prebuilt-only | -b}] [{--attr | -A}] [--from-expression] [-E] [--from-profile path] [--preserve-installed | -P]

Description

The upgrade operation creates a new user environment, based on the current generation of the active profile, in which all store paths are replaced for which there are newer versions in the set of paths described by args. Paths for which there are no newer versions are left untouched; this is not an error. It is also not an error if an element of args matches no installed derivations.

For a description of how args is mapped to a set of store paths, see --install. If args describes multiple store paths with the same symbolic name, only the one with the highest version is installed.

Flags

•   --lt

    Only upgrade a derivation to newer versions. This is the default.

•   --leq

    In addition to upgrading to newer versions, also “upgrade” to derivations that have the same version. Version are not a unique identification of a derivation, so there may be many derivations that have the same version. This flag may be useful to force “synchronisation” between the installed and available derivations.

•   --eq

    Only “upgrade” to derivations that have the same version. This may not seem very useful, but it actually is, e.g., when there is a new release of Nixpkgs and you want to replace installed applications with the same versions built against newer dependencies (to reduce the number of dependencies floating around on your system).

•   --always

    In addition to upgrading to newer versions, also “upgrade” to derivations that have the same or a lower version. I.e., derivations may actually be downgraded depending on what is available in the active Nix expression.

•   --prebuilt-only / -b

    Use only derivations for which a substitute is registered, i.e., there is a pre-built binary available that can be downloaded in lieu of building the derivation. Thus, no packages will be built from source.

•   --preserve-installed / -P

    Do not remove derivations with a name matching one of the derivations being installed. Usually, trying to have two versions of the same package installed in the same generation of a profile will lead to an error in building the generation, due to file name clashes between the two versions. However, this is not the case for all packages.

Options

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

•   --file / -f path

    Specifies the Nix expression (designated below as the active Nix expression) used by the --install, --upgrade, and --query --available operations to obtain derivations. The default is ~/.nix-defexpr.

    If the argument starts with http:// or https://, it is interpreted as the URL of a tarball that will be downloaded and unpacked to a temporary location. The tarball must include a single top-level directory containing at least a file named default.nix.

•   --profile / -p path

    Specifies the profile to be used by those operations that operate on a profile (designated below as the active profile). A profile is a sequence of user environments called generations, one of which is the current generation.

•   --dry-run

    For the --install, --upgrade, --uninstall, --switch-generation, --delete-generations and --rollback operations, this flag will cause nix-env to print what would be done if this flag had not been specified, without actually doing it.

    --dry-run also prints out which paths will be substituted (i.e., downloaded) and which paths will be built from source (because no substitute is available).

•   --system-filter system

    By default, operations such as --query --available show derivations matching any platform. This option allows you to use derivations for the specified platform system.

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.)

•   --arg-from-file name path

    Pass the contents of file path as the argument name to Nix functions.

•   --arg-from-stdin name

    Pass the contents of stdin as the argument name to Nix functions.

•   --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.

•   --eval-store store-url

    The URL to the Nix store to use for evaluation, i.e. where to store derivations (.drv files) and inputs referenced by them.

•   --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 / --include path

    Add an entry to the list of search paths used to resolve lookup paths. This option may be given multiple times.

    Paths added through -I take precedence over the nix-path configuration setting and the NIX_PATH environment variable.

•   --impure

    Allow access to mutable paths and repositories.

•   --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.

    Note

    See man nix.conf for overriding configuration settings with command line flags.

Environment variables

•   NIX_PROFILE

    Location of the Nix profile. Defaults to the target of the symlink ~/.nix-profile, if it exists, or /nix/var/nix/profiles/default otherwise.

Common Environment Variables

Most Nix commands interpret the following environment variables.

  Configuration environment variables

The following environment variables affect how Nix loads its configuration. See the configuration file documentation for full details.

•   NIX_CONF_DIR

    Overrides the system configuration directory.

•   NIX_USER_CONF_FILES

    Overrides the user configuration file locations.

•   NIX_CONFIG

    Provides configuration settings inline.

  Store setting environment variables

•   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. On Unix, the default is /nix/store, set at compile time by the libstore:store-dir build option. On Windows, there is no compile-time setting; the default is %PROGRAMDATA%\nix\store, determined at runtime using the %PROGRAMDATA% Known Folder.

    See the Store Types chapter; each store has a store setting linking back to this as its default.

•   NIX_LOG_DIR

    Overrides the location of the Nix log directory. On Unix, the default is /nix/var/log/nix, set at compile time by the log-dir build option. On Windows, there is no compile-time setting; the default is %PROGRAMDATA%\nix\log, determined at runtime using the %PROGRAMDATA% Known Folder.

    The Local Store, Local Daemon Store, and Experimental SSH Store with filesystem mounted have per-store settings that override this.

•   NIX_STATE_DIR

    Overrides the location of the Nix state directory. On Unix, the default is ${localstatedir}/nix, where localstatedir is a compile-time build option defaulting to /nix/var. On Windows, there is no compile-time setting; the default is %PROGRAMDATA%\nix\state, determined at runtime using the %PROGRAMDATA% Known Folder.

    The Local Store, Local Daemon Store, and Experimental SSH Store with filesystem mounted have per-store settings that override this.

•   NIX_DAEMON_SOCKET_PATH

    Overrides the path to the Unix domain socket used to communicate with the Nix daemon. Defaults to daemon-socket/socket within the state directory (see NIX_STATE_DIR).

    See the Local Daemon Store documentation for details on how the socket path is resolved.

•   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

    Overrides the store setting.

  Nix language evaluator settings

•   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.

•   NIX_PATH

    A colon-separated list of search path entries used to resolve lookup paths.

    This environment variable overrides the value of the nix-path configuration setting.

    It can be extended using the -I option.

        Example

        $ export NIX_PATH=/home/eelco/Dev:nixos-config=/etc/nixos

    If NIX_PATH is set to an empty string, resolving search paths will always fail.

        Example

        $ NIX_PATH= nix-instantiate --eval '<nixpkgs>'
        error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I)

  User Directories

Nix supports per-user configuration, state, and cache directories. The following environment variables override the locations for these directories:

•   [user configuration directory]{#user-conf-dir}: [NIX_CONFIG_HOME]{#env-NIXCONFIGHOME}

•   user state directory: [NIX_STATE_HOME]{#env-NIXSTATEHOME}

•   user cache directory: [NIX_CACHE_HOME]{#env-NIXCACHEHOME}

When these are not set, the defaults depend on the platform:

•   On Unix, the XDG base directories: $XDG_CONFIG_HOME/nix, $XDG_STATE_HOME/nix, $XDG_CACHE_HOME/nix

•   On Windows, the Windows Known Folders: %APPDATA%\nix\config, %LOCALAPPDATA%\nix\state, %LOCALAPPDATA%\nix\cache

For backwards compatibility, legacy Nix commands (e.g. nix-env, nix-channel) use dotfiles in $HOME instead of these directories unless use-xdg-base-directories is enabled. New Nix commands (experimental) use the proper directories by default.

When use-xdg-base-directories is enabled, the configuration directory is resolved as:

1.  $NIX_CONFIG_HOME, if it is defined

2.  Otherwise, the platform default (e.g. $XDG_CONFIG_HOME/nix on Unix)

Likewise for the state and cache directories.

  Miscellaneous 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.

  Appendix: OS-specific conventions

This information is not Nix-specific, but is referenced above.

  Unix: XDG Base Directories

The XDG Base Directory Specification defines standard locations for user-specific configuration, state, and cache files on Unix systems.

The following environment variables are used:

•   [XDG_CONFIG_HOME]{#env-XDGCONFIGHOME} (default ~/.config)

•   [XDG_STATE_HOME]{#env-XDGSTATEHOME} (default ~/.local/state)

•   [XDG_CACHE_HOME]{#env-XDGCACHEHOME} (default ~/.cache)

•   [XDG_CONFIG_DIRS]{#env-XDGCONFIGDIRS} (default /etc/xdg) — colon-separated list of additional configuration base directories, searched after XDG_CONFIG_HOME

  Windows: Known Folders

On Windows, Known Folders provide standard locations for application data on Windows.

The relevant folders are:

•   [%APPDATA%]{#env-APPDATA} — per-user roaming application data

•   [%LOCALAPPDATA%]{#env-LOCALAPPDATA} — per-user local application data

•   [%PROGRAMDATA%]{#env-PROGRAMDATA} — system-wide application data

Examples

    $ nix-env --upgrade --attr nixpkgs.gcc
    upgrading `gcc-3.3.1' to `gcc-3.4'

When there are no updates available, nothing will happen:

    $ nix-env --upgrade --attr nixpkgs.pan

Using -A is preferred when possible, as it is faster and unambiguous but it is also possible to upgrade to a specific version by matching the derivation name:

    $ nix-env --upgrade gcc-3.3.2 --always
    upgrading `gcc-3.4' to `gcc-3.3.2'

To try to upgrade everything (matching packages based on the part of the derivation name without version):

    $ nix-env --upgrade
    upgrading `hello-2.1.2' to `hello-2.1.3'
    upgrading `mozilla-1.2' to `mozilla-1.4'

Versions

The upgrade operation determines whether a derivation y is an upgrade of a derivation x by looking at their respective name attributes. The names (e.g., gcc-3.3.1 are split into two parts: the package name (gcc), and the version (3.3.1). The version part starts after the first dash not followed by a letter. y is considered an upgrade of x if their package names match, and the version of y is higher than that of x.

The versions are compared by splitting them into contiguous components of numbers and letters. E.g., 3.3.1pre5 is split into [3, 3, 1, "pre", 5]. These lists are then compared lexicographically (from left to right). Corresponding components a and b are compared as follows. If they are both numbers, integer comparison is used. If a is an empty string and b is a number, a is considered less than b. The special string component pre (for pre-release) is considered to be less than other components. String components are considered less than number components. Otherwise, they are compared lexicographically (i.e., using case-sensitive string comparison).

This is illustrated by the following examples:

    1.0 < 2.3
    2.1 < 2.3
    2.3 = 2.3
    2.5 > 2.3
    3.1 > 2.3
    2.3.1 > 2.3
    2.3.1 > 2.3a
    2.3pre1 < 2.3
    2.3pre3 < 2.3pre12
    2.3a < 2.3c
    2.3pre1 < 2.3c
    2.3pre1 < 2.3q