path: root/doc/manual/src/command-ref/conf-file.md

Title: nix.conf

# Name

`nix.conf` - Nix configuration file

# Description

By default Nix reads settings from the following places:

  - The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e.
    `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if
    `NIX_CONF_DIR` is set. Values loaded in this file are not forwarded
    to the Nix daemon. The client assumes that the daemon has already
    loaded them.

  - If `NIX_USER_CONF_FILES` is set, then each path separated by `:`
    will be loaded in reverse order.

    Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS`
    and `XDG_CONFIG_HOME`. If these are unset, it will look in
    `$HOME/.config/nix.conf`.

The configuration files consist of `name =
value` pairs, one per line. Other files can be included with a line like
`include
path`, where *path* is interpreted relative to the current conf file and
a missing file is an error unless `!include` is used instead. Comments
start with a `#` character. Here is an example configuration file:

    keep-outputs = true       # Nice for developers
    keep-derivations = true   # Idem

You can override settings on the command line using the `--option` flag,
e.g. `--option keep-outputs
false`.

The following settings are currently available:

  - `allowed-uris`  
    A list of URI prefixes to which access is allowed in restricted
    evaluation mode. For example, when set to
    `https://github.com/NixOS`, builtin functions such as `fetchGit` are
    allowed to access `https://github.com/NixOS/patchelf.git`.

  - `allow-import-from-derivation`  
    By default, Nix allows you to `import` from a derivation, allowing
    building at evaluation time. With this option set to false, Nix will
    throw an error when evaluating an expression that uses this feature,
    allowing users to ensure their evaluation will not require any
    builds to take place.

  - `allow-new-privileges`  
    (Linux-specific.) By default, builders on Linux cannot acquire new
    privileges by calling setuid/setgid programs or programs that have
    file capabilities. For example, programs such as `sudo` or `ping`
    will fail. (Note that in sandbox builds, no such programs are
    available unless you bind-mount them into the sandbox via the
    `sandbox-paths` option.) You can allow the use of such programs by
    enabling this option. This is impure and usually undesirable, but
    may be useful in certain scenarios (e.g. to spin up containers or
    set up userspace network interfaces in tests).

  - `allowed-users`  
    A list of names of users (separated by whitespace) that are allowed
    to connect to the Nix daemon. As with the `trusted-users` option,
    you can specify groups by prefixing them with `@`. Also, you can
    allow all users by specifying `*`. The default is `*`.
    
    Note that trusted users are always allowed to connect.

  - `auto-optimise-store`  
    If set to `true`, Nix automatically detects files in the store that
    have identical contents, and replaces them with hard links to a
    single copy. This saves disk space. If set to `false` (the default),
    you can still run `nix-store
                    --optimise` to get rid of duplicate files.

  - `builders`  
    A list of machines on which to perform builds.

  - `builders-use-substitutes`  
    If set to `true`, Nix will instruct remote build machines to use
    their own binary substitutes if available. In practical terms, this
    means that remote hosts will fetch as many build dependencies as
    possible from their own substitutes (e.g, from `cache.nixos.org`),
    instead of waiting for this host to upload them all. This can
    drastically reduce build times if the network connection between
    this computer and the remote build host is slow. Defaults to
    `false`.

  - `build-users-group`  
    This options specifies the Unix group containing the Nix build user
    accounts. In multi-user Nix installations, builds should not be
    performed by the Nix account since that would allow users to
    arbitrarily modify the Nix store and database by supplying specially
    crafted builders; and they cannot be performed by the calling user
    since that would allow him/her to influence the build result.
    
    Therefore, if this option is non-empty and specifies a valid group,
    builds will be performed under the user accounts that are a member
    of the group specified here (as listed in `/etc/group`). Those user
    accounts should not be used for any other purpose\!
    
    Nix will never run two builds under the same user account at the
    same time. This is to prevent an obvious security hole: a malicious
    user writing a Nix expression that modifies the build result of a
    legitimate Nix expression being built by another user. Therefore it
    is good to have as many Nix build user accounts as you can spare.
    (Remember: uids are cheap.)
    
    The build users should have permission to create files in the Nix
    store, but not delete them. Therefore, `/nix/store` should be owned
    by the Nix account, its group should be the group specified here,
    and its mode should be `1775`.
    
    If the build users group is empty, builds will be performed under
    the uid of the Nix process (that is, the uid of the caller if
    `NIX_REMOTE` is empty, the uid under which the Nix daemon runs if
    `NIX_REMOTE` is `daemon`). Obviously, this should not be used in
    multi-user settings with untrusted users.

  - `compress-build-log`  
    If set to `true` (the default), build logs written to
    `/nix/var/log/nix/drvs` will be compressed on the fly using bzip2.
    Otherwise, they will not be compressed.

  - `connect-timeout`  
    The timeout (in seconds) for establishing connections in the binary
    cache substituter. It corresponds to `curl`’s `--connect-timeout`
    option.

  - `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 can be overridden using the `--cores`
    command line switch and defaults to `1`. The value `0` means that
    the builder should use all available CPU cores in the system.

  - `diff-hook`  
    Absolute path to an executable capable of diffing build results. The
    hook executes if [varlistentry\_title](#conf-run-diff-hook) is true,
    and the output of a build is known to not be the same. This program
    is not executed to determine if two results are the same.
    
    The diff hook is executed by the same user and group who ran the
    build. However, the diff hook does not have write access to the
    store path just built.
    
    The diff hook program receives three parameters:
    
    1.  A path to the previous build's results
    
    2.  A path to the current build's results
    
    3.  The path to the build's derivation
    
    4.  The path to the build's scratch directory. This directory will
        exist only if the build was run with `--keep-failed`.
    
    The stderr and stdout output from the diff hook will not be
    displayed to the user. Instead, it will print to the nix-daemon's
    log.
    
    When using the Nix daemon, `diff-hook` must be set in the `nix.conf`
    configuration file, and cannot be passed at the command line.

  - `enforce-determinism`  
    See [varlistentry\_title](#conf-repeat).

  - `extra-sandbox-paths`  
    A list of additional paths appended to `sandbox-paths`. Useful if
    you want to extend its default value.

  - `extra-platforms`  
    Platforms other than the native one which this machine is capable of
    building for. This can be useful for supporting additional
    architectures on compatible machines: i686-linux can be built on
    x86\_64-linux machines (and the default for this setting reflects
    this); armv7 is backwards-compatible with armv6 and armv5tel; some
    aarch64 machines can also natively run 32-bit ARM code; and
    qemu-user may be used to support non-native platforms (though this
    may be slow and buggy). Most values for this are not enabled by
    default because build systems will often misdetect the target
    platform and generate incompatible code, so you may wish to
    cross-check the results of using this option against proper
    natively-built versions of your derivations.

  - `extra-substituters`  
    Additional binary caches appended to those specified in
    `substituters`. When used by unprivileged users, untrusted
    substituters (i.e. those not listed in `trusted-substituters`) are
    silently ignored.

  - `fallback`  
    If set to `true`, Nix will fall back to building from source if a
    binary substitute fails. This is equivalent to the `--fallback`
    flag. The default is `false`.

  - `fsync-metadata`  
    If set to `true`, changes to the Nix store metadata (in
    `/nix/var/nix/db`) are synchronously flushed to disk. This improves
    robustness in case of system crashes, but reduces performance. The
    default is `true`.

  - `hashed-mirrors`  
    A list of web servers used by `builtins.fetchurl` to obtain files by
    hash. The default is `http://tarballs.nixos.org/`. Given a hash type
    *ht* and a base-16 hash *h*, Nix will try to download the file from
    `hashed-mirror/ht/h`. This allows files to be downloaded even if
    they have disappeared from their original URI. For example, given
    the default mirror `http://tarballs.nixos.org/`, when building the
    derivation
    
        builtins.fetchurl {
          url = "https://example.org/foo-1.2.3.tar.xz";
          sha256 = "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae";
        }
    
    Nix will attempt to download this file from
    `http://tarballs.nixos.org/sha256/2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae`
    first. If it is not available there, if will try the original URI.

  - `http-connections`  
    The maximum number of parallel TCP connections used to fetch files
    from binary caches and by other downloads. It defaults to 25. 0
    means no limit.

  - `keep-build-log`  
    If set to `true` (the default), Nix will write the build log of a
    derivation (i.e. the standard output and error of its builder) to
    the directory `/nix/var/log/nix/drvs`. The build log can be
    retrieved using the command `nix-store -l
                    path`.

  - `keep-derivations`  
    If `true` (default), the garbage collector will keep the derivations
    from which non-garbage store paths were built. If `false`, they will
    be deleted unless explicitly registered as a root (or reachable from
    other roots).
    
    Keeping derivation around is useful for querying and traceability
    (e.g., it allows you to ask with what dependencies or options a
    store path was built), so by default this option is on. Turn it off
    to save a bit of disk space (or a lot if `keep-outputs` is also
    turned on).

  - `keep-env-derivations`  
    If `false` (default), derivations are not stored in Nix user
    environments. That is, the derivations of any build-time-only
    dependencies may be garbage-collected.
    
    If `true`, when you add a Nix derivation to a user environment, the
    path of the derivation is stored in the user environment. Thus, the
    derivation will not be garbage-collected until the user environment
    generation is deleted (`nix-env --delete-generations`). To prevent
    build-time-only dependencies from being collected, you should also
    turn on `keep-outputs`.
    
    The difference between this option and `keep-derivations` is that
    this one is “sticky”: it applies to any user environment created
    while this option was enabled, while `keep-derivations` only applies
    at the moment the garbage collector is run.

  - `keep-outputs`  
    If `true`, the garbage collector will keep the outputs of
    non-garbage derivations. If `false` (default), outputs will be
    deleted unless they are GC roots themselves (or reachable from other
    roots).
    
    In general, outputs must be registered as roots separately. However,
    even if the output of a derivation is registered as a root, the
    collector will still delete store paths that are used only at build
    time (e.g., the C compiler, or source tarballs downloaded from the
    network). To prevent it from doing so, set this option to `true`.

  - `max-build-log-size`  
    This option defines the maximum number of bytes that a builder can
    write to its stdout/stderr. If the builder exceeds this limit, it’s
    killed. A value of `0` (the default) means that there is no limit.

  - `max-free`  
    When a garbage collection is triggered by the `min-free` option, it
    stops as soon as `max-free` bytes are available. The default is
    infinity (i.e. delete all garbage).

  - `max-jobs`  
    This option defines the maximum number of jobs that Nix will try to
    build in parallel. The default is `1`. The special value `auto`
    causes Nix to use the number of CPUs in your system. `0` is useful
    when using remote builders to prevent any local builds (except for
    `preferLocalBuild` derivation attribute which executes locally
    regardless). It can be overridden using the `--max-jobs` (`-j`)
    command line switch.

  - `max-silent-time`  
    This option defines the maximum number of seconds that a builder can
    go without producing any data on standard output or standard error.
    This is useful (for instance in an automated build system) to catch
    builds that are stuck in an infinite loop, or to catch remote builds
    that are hanging due to network problems. It can be overridden using
    the `--max-silent-time` command line switch.
    
    The value `0` means that there is no timeout. This is also the
    default.

  - `min-free`  
    When free disk space in `/nix/store` drops below `min-free` during a
    build, Nix performs a garbage-collection until `max-free` bytes are
    available or there is no more garbage. A value of `0` (the default)
    disables this feature.

  - `narinfo-cache-negative-ttl`  
    The TTL in seconds for negative lookups. If a store path is queried
    from a substituter but was not found, there will be a negative
    lookup cached in the local disk cache database for the specified
    duration.

  - `narinfo-cache-positive-ttl`  
    The TTL in seconds for positive lookups. If a store path is queried
    from a substituter, the result of the query will be cached in the
    local disk cache database including some of the NAR metadata. The
    default TTL is a month, setting a shorter TTL for positive lookups
    can be useful for binary caches that have frequent garbage
    collection, in which case having a more frequent cache invalidation
    would prevent trying to pull the path again and failing with a hash
    mismatch if the build isn't reproducible.

  - `netrc-file`  
    If set to an absolute path to a `netrc` file, Nix will use the HTTP
    authentication credentials in this file when trying to download from
    a remote host through HTTP or HTTPS. Defaults to
    `$NIX_CONF_DIR/netrc`.
    
    The `netrc` file consists of a list of accounts in the following
    format:
    
        machine my-machine
        login my-username
        password my-password
    
    For the exact syntax, see [the `curl`
    documentation.](https://ec.haxx.se/usingcurl-netrc.html)
    
    > **Note**
    > 
    > This must be an absolute path, and `~` is not resolved. For
    > example, `~/.netrc` won't resolve to your home directory's
    > `.netrc`.

  - `plugin-files`  
    A list of plugin files to be loaded by Nix. Each of these files will
    be dlopened by Nix, allowing them to affect execution through static
    initialization. In particular, these plugins may construct static
    instances of RegisterPrimOp to add new primops or constants to the
    expression language, RegisterStoreImplementation to add new store
    implementations, RegisterCommand to add new subcommands to the `nix`
    command, and RegisterSetting to add new nix config settings. See the
    constructors for those types for more details.
    
    Since these files are loaded into the same address space as Nix
    itself, they must be DSOs compatible with the instance of Nix
    running at the time (i.e. compiled against the same headers, not
    linked to any incompatible libraries). They should not be linked to
    any Nix libs directly, as those will be available already at load
    time.
    
    If an entry in the list is a directory, all files in the directory
    are loaded as plugins (non-recursively).

  - `pre-build-hook`  
    If set, the path to a program that can set extra derivation-specific
    settings for this system. This is used for settings that can't be
    captured by the derivation model itself and are too variable between
    different versions of the same system to be hard-coded into nix.
    
    The hook is passed the derivation path and, if sandboxes are
    enabled, the sandbox directory. It can then modify the sandbox and
    send a series of commands to modify various settings to stdout. The
    currently recognized commands are:
    
      - `extra-sandbox-paths`  
        Pass a list of files and directories to be included in the
        sandbox for this build. One entry per line, terminated by an
        empty line. Entries have the same format as `sandbox-paths`.

  - `post-build-hook`  
    Optional. The path to a program to execute after each build.
    
    This option is only settable in the global `nix.conf`, or on the
    command line by trusted users.
    
    When using the nix-daemon, the daemon executes the hook as `root`.
    If the nix-daemon is not involved, the hook runs as the user
    executing the nix-build.
    
      - The hook executes after an evaluation-time build.
    
      - The hook does not execute on substituted paths.
    
      - The hook's output always goes to the user's terminal.
    
      - If the hook fails, the build succeeds but no further builds
        execute.
    
      - The hook executes synchronously, and blocks other builds from
        progressing while it runs.
    
    The program executes with no arguments. The program's environment
    contains the following environment variables:
    
      - `DRV_PATH`  
        The derivation for the built paths.
        
        Example:
        `/nix/store/5nihn1a7pa8b25l9zafqaqibznlvvp3f-bash-4.4-p23.drv`
    
      - `OUT_PATHS`  
        Output paths of the built derivation, separated by a space
        character.
        
        Example:
        `/nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev
        /nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
        /nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
        /nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
        /nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23`.

  - `repeat`  
    How many times to repeat builds to check whether they are
    deterministic. The default value is 0. If the value is non-zero,
    every build is repeated the specified number of times. If the
    contents of any of the runs differs from the previous ones and
    [varlistentry\_title](#conf-enforce-determinism) is true, the build
    is rejected and the resulting store paths are not registered as
    “valid” in Nix’s database.

  - `require-sigs`  
    If set to `true` (the default), any non-content-addressed path added
    or copied to the Nix store (e.g. when substituting from a binary
    cache) must have a valid signature, that is, be signed using one of
    the keys listed in `trusted-public-keys` or `secret-key-files`. Set
    to `false` to disable signature checking.

  - `restrict-eval`  
    If set to `true`, the Nix evaluator will not allow access to any
    files outside of the Nix search path (as set via the `NIX_PATH`
    environment variable or the `-I` option), or to URIs outside of
    `allowed-uri`. The default is `false`.

  - `run-diff-hook`  
    If true, enable the execution of the `diff-hook` program.
    
    When using the Nix daemon, `run-diff-hook` must be set in the
    `nix.conf` configuration file, and cannot be passed at the command
    line.

  - `sandbox`  
    If set to `true`, builds will be performed in a *sandboxed
    environment*, i.e., they’re isolated from the normal file system
    hierarchy and will only see their dependencies in the Nix store, the
    temporary build directory, private versions of `/proc`, `/dev`,
    `/dev/shm` and `/dev/pts` (on Linux), and the paths configured with
    the [`sandbox-paths` option](#conf-sandbox-paths). This is useful to
    prevent undeclared dependencies on files in directories such as
    `/usr/bin`. In addition, on Linux, builds run in private PID, mount,
    network, IPC and UTS namespaces to isolate them from other processes
    in the system (except that fixed-output derivations do not run in
    private network namespace to ensure they can access the network).
    
    Currently, sandboxing only work on Linux and macOS. The use of a
    sandbox requires that Nix is run as root (so you should use the
    [“build users” feature](#conf-build-users-group) to perform the
    actual builds under different users than root).
    
    If this option is set to `relaxed`, then fixed-output derivations
    and derivations that have the `__noChroot` attribute set to `true`
    do not run in sandboxes.
    
    The default is `true` on Linux and `false` on all other platforms.

  - `sandbox-dev-shm-size`  
    This option determines the maximum size of the `tmpfs` filesystem
    mounted on `/dev/shm` in Linux sandboxes. For the format, see the
    description of the `size` option of `tmpfs` in mount8. The default
    is `50%`.

  - `sandbox-paths`  
    A list of paths bind-mounted into Nix sandbox environments. You can
    use the syntax `target=source` to mount a path in a different
    location in the sandbox; for instance, `/bin=/nix-bin` will mount
    the path `/nix-bin` as `/bin` inside the sandbox. If *source* is
    followed by `?`, then it is not an error if *source* does not exist;
    for example, `/dev/nvidiactl?` specifies that `/dev/nvidiactl` will
    only be mounted in the sandbox if it exists in the host filesystem.
    
    Depending on how Nix was built, the default value for this option
    may be empty or provide `/bin/sh` as a bind-mount of `bash`.

  - `secret-key-files`  
    A whitespace-separated list of files containing secret (private)
    keys. These are used to sign locally-built paths. They can be
    generated using `nix-store
                    --generate-binary-cache-key`. The corresponding public key can be
    distributed to other users, who can add it to `trusted-public-keys`
    in their `nix.conf`.

  - `show-trace`  
    Causes Nix to print out a stack trace in case of Nix expression
    evaluation errors.

  - `substitute`  
    If set to `true` (default), Nix will use binary substitutes if
    available. This option can be disabled to force building from
    source.

  - `stalled-download-timeout`  
    The timeout (in seconds) for receiving data from servers during
    download. Nix cancels idle downloads after this timeout's duration.

  - `substituters`  
    A list of URLs of substituters, separated by whitespace. The default
    is `https://cache.nixos.org`.

  - `system`  
    This option specifies the canonical Nix system name of the current
    installation, such as `i686-linux` or `x86_64-darwin`. Nix can only
    build derivations whose `system` attribute equals the value
    specified here. In general, it never makes sense to modify this
    value from its default, since you can use it to ‘lie’ about the
    platform you are building on (e.g., perform a Mac OS build on a
    Linux machine; the result would obviously be wrong). It only makes
    sense if the Nix binaries can run on multiple platforms, e.g.,
    ‘universal binaries’ that run on `x86_64-linux` and `i686-linux`.
    
    It defaults to the canonical Nix system name detected by `configure`
    at build time.

  - `system-features`  
    A set of system “features” supported by this machine, e.g. `kvm`.
    Derivations can express a dependency on such features through the
    derivation attribute `requiredSystemFeatures`. For example, the
    attribute
    
        requiredSystemFeatures = [ "kvm" ];
    
    ensures that the derivation can only be built on a machine with the
    `kvm` feature.
    
    This setting by default includes `kvm` if `/dev/kvm` is accessible,
    and the pseudo-features `nixos-test`, `benchmark` and `big-parallel`
    that are used in Nixpkgs to route builds to specific machines.

  - `tarball-ttl`  
    Default: `3600` seconds.
    
    The number of seconds a downloaded tarball is considered fresh. If
    the cached tarball is stale, Nix will check whether it is still up
    to date using the ETag header. Nix will download a new version if
    the ETag header is unsupported, or the cached ETag doesn't match.
    
    Setting the TTL to `0` forces Nix to always check if the tarball is
    up to date.
    
    Nix caches tarballs in `$XDG_CACHE_HOME/nix/tarballs`.
    
    Files fetched via `NIX_PATH`, `fetchGit`, `fetchMercurial`,
    `fetchTarball`, and `fetchurl` respect this TTL.

  - `timeout`  
    This option defines the maximum number of seconds that a builder can
    run. This is useful (for instance in an automated build system) to
    catch builds that are stuck in an infinite loop but keep writing to
    their standard output or standard error. It can be overridden using
    the `--timeout` command line switch.
    
    The value `0` means that there is no timeout. This is also the
    default.

  - `trace-function-calls`  
    Default: `false`.
    
    If set to `true`, the Nix evaluator will trace every function call.
    Nix will print a log message at the "vomit" level for every function
    entrance and function exit.
    
        function-trace entered undefined position at 1565795816999559622
        function-trace exited undefined position at 1565795816999581277
        function-trace entered /nix/store/.../example.nix:226:41 at 1565795253249935150
        function-trace exited /nix/store/.../example.nix:226:41 at 1565795253249941684
    
    The `undefined position` means the function call is a builtin.
    
    Use the `contrib/stack-collapse.py` script distributed with the Nix
    source code to convert the trace logs in to a format suitable for
    `flamegraph.pl`.

  - `trusted-public-keys`  
    A whitespace-separated list of public keys. When paths are copied
    from another Nix store (such as a binary cache), they must be signed
    with one of these keys. For example:
    `cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
                    hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=`.

  - `trusted-substituters`  
    A list of URLs of substituters, separated by whitespace. These are
    not used by default, but can be enabled by users of the Nix daemon
    by specifying `--option
                    substituters urls` on the command line. Unprivileged users are only
    allowed to pass a subset of the URLs listed in `substituters` and
    `trusted-substituters`.

  - `trusted-users`  
    A list of names of users (separated by whitespace) that have
    additional rights when connecting to the Nix daemon, such as the
    ability to specify additional binary caches, or to import unsigned
    NARs. You can also specify groups by prefixing them with `@`; for
    instance, `@wheel` means all users in the `wheel` group. The default
    is `root`.
    
    > **Warning**
    > 
    > Adding a user to `trusted-users` is essentially equivalent to
    > giving that user root access to the system. For example, the user
    > can set `sandbox-paths` and thereby obtain read access to
    > directories that are otherwise inacessible to them.

## Deprecated Settings

  - `binary-caches`  
    *Deprecated:* `binary-caches` is now an alias to
    [varlistentry\_title](#conf-substituters).

  - `binary-cache-public-keys`  
    *Deprecated:* `binary-cache-public-keys` is now an alias to
    [varlistentry\_title](#conf-trusted-public-keys).

  - `build-compress-log`  
    *Deprecated:* `build-compress-log` is now an alias to
    [varlistentry\_title](#conf-compress-build-log).

  - `build-cores`  
    *Deprecated:* `build-cores` is now an alias to
    [varlistentry\_title](#conf-cores).

  - `build-extra-chroot-dirs`  
    *Deprecated:* `build-extra-chroot-dirs` is now an alias to
    [varlistentry\_title](#conf-extra-sandbox-paths).

  - `build-extra-sandbox-paths`  
    *Deprecated:* `build-extra-sandbox-paths` is now an alias to
    [varlistentry\_title](#conf-extra-sandbox-paths).

  - `build-fallback`  
    *Deprecated:* `build-fallback` is now an alias to
    [varlistentry\_title](#conf-fallback).

  - `build-max-jobs`  
    *Deprecated:* `build-max-jobs` is now an alias to
    [varlistentry\_title](#conf-max-jobs).

  - `build-max-log-size`  
    *Deprecated:* `build-max-log-size` is now an alias to
    [varlistentry\_title](#conf-max-build-log-size).

  - `build-max-silent-time`  
    *Deprecated:* `build-max-silent-time` is now an alias to
    [varlistentry\_title](#conf-max-silent-time).

  - `build-repeat`  
    *Deprecated:* `build-repeat` is now an alias to
    [varlistentry\_title](#conf-repeat).

  - `build-timeout`  
    *Deprecated:* `build-timeout` is now an alias to
    [varlistentry\_title](#conf-timeout).

  - `build-use-chroot`  
    *Deprecated:* `build-use-chroot` is now an alias to
    [varlistentry\_title](#conf-sandbox).

  - `build-use-sandbox`  
    *Deprecated:* `build-use-sandbox` is now an alias to
    [varlistentry\_title](#conf-sandbox).

  - `build-use-substitutes`  
    *Deprecated:* `build-use-substitutes` is now an alias to
    [varlistentry\_title](#conf-substitute).

  - `gc-keep-derivations`  
    *Deprecated:* `gc-keep-derivations` is now an alias to
    [varlistentry\_title](#conf-keep-derivations).

  - `gc-keep-outputs`  
    *Deprecated:* `gc-keep-outputs` is now an alias to
    [varlistentry\_title](#conf-keep-outputs).

  - `env-keep-derivations`  
    *Deprecated:* `env-keep-derivations` is now an alias to
    [varlistentry\_title](#conf-keep-env-derivations).

  - `extra-binary-caches`  
    *Deprecated:* `extra-binary-caches` is now an alias to
    [varlistentry\_title](#conf-extra-substituters).

  - `trusted-binary-caches`  
    *Deprecated:* `trusted-binary-caches` is now an alias to
    [varlistentry\_title](#conf-trusted-substituters).