nixpkgs/pkgs/build-support/trivial-builders/default.nix

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{ lib, stdenv, stdenvNoCC, lndir, runtimeShell, shellcheck, haskell }:
let
inherit (lib)
optionalAttrs
warn
;
in
rec {
/* Run the shell command `buildCommand' to produce a store path named
`name'. The attributes in `env' are added to the environment
prior to running the command. By default `runCommand` runs in a
stdenv with no compiler environment. `runCommandCC` uses the default
stdenv, `pkgs.stdenv`.
Example:
runCommand "name" {envVariable = true;} ''echo hello > $out''
runCommandCC "name" {} ''gcc -o myfile myfile.c; cp myfile $out'';
The `*Local` variants force a derivation to be built locally,
it is not substituted.
This is intended for very cheap commands (<1s execution time).
It saves on the network roundrip and can speed up a build.
It is the same as adding the special fields
`preferLocalBuild = true;`
`allowSubstitutes = false;`
to a derivations attributes.
*/
runCommand = name: env: runCommandWith {
stdenv = stdenvNoCC;
runLocal = false;
inherit name;
derivationArgs = env;
};
runCommandLocal = name: env: runCommandWith {
stdenv = stdenvNoCC;
runLocal = true;
inherit name;
derivationArgs = env;
};
runCommandCC = name: env: runCommandWith {
stdenv = stdenv;
runLocal = false;
inherit name;
derivationArgs = env;
};
# `runCommandCCLocal` left out on purpose.
# We shouldnt force the user to have a cc in scope.
/* Generalized version of the `runCommand`-variants
which does customized behavior via a single
attribute set passed as the first argument
instead of having a lot of variants like
`runCommand*`. Additionally it allows changing
the used `stdenv` freely and has a more explicit
approach to changing the arguments passed to
`stdenv.mkDerivation`.
*/
runCommandWith =
let
# prevent infinite recursion for the default stdenv value
defaultStdenv = stdenv;
in
{
# which stdenv to use, defaults to a stdenv with a C compiler, pkgs.stdenv
stdenv ? defaultStdenv
# whether to build this derivation locally instead of substituting
, runLocal ? false
# extra arguments to pass to stdenv.mkDerivation
, derivationArgs ? {}
# name of the resulting derivation
, name
# TODO(@Artturin): enable strictDeps always
}: buildCommand:
stdenv.mkDerivation ({
enableParallelBuilding = true;
inherit buildCommand name;
passAsFile = [ "buildCommand" ]
++ (derivationArgs.passAsFile or []);
}
// lib.optionalAttrs (! derivationArgs?meta) {
pos = let args = builtins.attrNames derivationArgs; in
if builtins.length args > 0
then builtins.unsafeGetAttrPos (builtins.head args) derivationArgs
else null;
}
// (lib.optionalAttrs runLocal {
preferLocalBuild = true;
allowSubstitutes = false;
})
// builtins.removeAttrs derivationArgs [ "passAsFile" ]);
/* Writes a text file to the nix store.
The contents of text is added to the file in the store.
Example:
# Writes my-file to /nix/store/<store path>
writeTextFile {
name = "my-file";
text = ''
Contents of File
'';
}
See also the `writeText` helper function below.
# Writes executable my-file to /nix/store/<store path>/bin/my-file
writeTextFile {
name = "my-file";
text = ''
Contents of File
'';
executable = true;
destination = "/bin/my-file";
}
*/
writeTextFile =
{ name # the name of the derivation
, text
, executable ? false # run chmod +x ?
, destination ? "" # relative path appended to $out eg "/bin/foo"
, checkPhase ? "" # syntax checks, e.g. for scripts
, meta ? { }
, allowSubstitutes ? false
, preferLocalBuild ? true
}:
let
matches = builtins.match "/bin/([^/]+)" destination;
in
runCommand name
{ inherit text executable checkPhase allowSubstitutes preferLocalBuild;
passAsFile = [ "text" ];
meta = lib.optionalAttrs (executable && matches != null) {
mainProgram = lib.head matches;
} // meta;
}
''
target=$out${lib.escapeShellArg destination}
mkdir -p "$(dirname "$target")"
if [ -e "$textPath" ]; then
mv "$textPath" "$target"
else
echo -n "$text" > "$target"
fi
if [ -n "$executable" ]; then
chmod +x "$target"
fi
eval "$checkPhase"
'';
/*
Writes a text file to nix store with no optional parameters available.
Example:
# Writes contents of file to /nix/store/<store path>
writeText "my-file"
''
Contents of File
'';
*/
writeText = name: text: writeTextFile {inherit name text;};
/*
Writes a text file to nix store in a specific directory with no
optional parameters available.
Example:
# Writes contents of file to /nix/store/<store path>/share/my-file
writeTextDir "share/my-file"
''
Contents of File
'';
*/
writeTextDir = path: text: writeTextFile {
inherit text;
name = builtins.baseNameOf path;
destination = "/${path}";
};
/*
Writes a text file to /nix/store/<store path> and marks the file as
executable.
If passed as a build input, will be used as a setup hook. This makes setup
hooks more efficient to create: you don't need a derivation that copies
them to $out/nix-support/setup-hook, instead you can use the file as is.
Example:
# Writes my-file to /nix/store/<store path> and makes executable
writeScript "my-file"
''
Contents of File
'';
*/
writeScript = name: text: writeTextFile {inherit name text; executable = true;};
/*
Writes a text file to /nix/store/<store path>/bin/<name> and
marks the file as executable.
Example:
# Writes my-file to /nix/store/<store path>/bin/my-file and makes executable.
writeScriptBin "my-file"
''
Contents of File
'';
*/
writeScriptBin = name: text: writeTextFile {
inherit name text;
executable = true;
destination = "/bin/${name}";
};
/*
Similar to writeScript. Writes a Shell script and checks its syntax.
Automatically includes interpreter above the contents passed.
Example:
# Writes my-file to /nix/store/<store path> and makes executable.
writeShellScript "my-file"
''
Contents of File
'';
*/
writeShellScript = name: text:
writeTextFile {
inherit name;
executable = true;
text = ''
#!${runtimeShell}
${text}
'';
checkPhase = ''
${stdenv.shellDryRun} "$target"
'';
};
/*
Similar to writeShellScript and writeScriptBin.
Writes an executable Shell script to /nix/store/<store path>/bin/<name> and checks its syntax.
Automatically includes interpreter above the contents passed.
Example:
# Writes my-file to /nix/store/<store path>/bin/my-file and makes executable.
writeShellScriptBin "my-file"
''
Contents of File
'';
*/
writeShellScriptBin = name : text :
writeTextFile {
inherit name;
executable = true;
destination = "/bin/${name}";
text = ''
#!${runtimeShell}
${text}
'';
checkPhase = ''
${stdenv.shellDryRun} "$target"
'';
};
/*
Similar to writeShellScriptBin and writeScriptBin.
Writes an executable Shell script to /nix/store/<store path>/bin/<name> and
checks its syntax with shellcheck and the shell's -n option.
Automatically includes sane set of shellopts (errexit, nounset, pipefail)
and handles creation of PATH based on runtimeInputs
Note that the checkPhase uses stdenv.shell for the test run of the script,
while the generated shebang uses runtimeShell. If, for whatever reason,
those were to mismatch you might lose fidelity in the default checks.
Example:
Writes my-file to /nix/store/<store path>/bin/my-file and makes executable.
writeShellApplication {
name = "my-file";
runtimeInputs = [ curl w3m ];
text = ''
curl -s 'https://nixos.org' | w3m -dump -T text/html
'';
}
*/
writeShellApplication =
{ name
, text
, runtimeInputs ? [ ]
, checkPhase ? null
}:
writeTextFile {
inherit name;
executable = true;
destination = "/bin/${name}";
allowSubstitutes = true;
preferLocalBuild = false;
text = ''
#!${runtimeShell}
set -o errexit
set -o nounset
set -o pipefail
'' + lib.optionalString (runtimeInputs != [ ]) ''
export PATH="${lib.makeBinPath runtimeInputs}:$PATH"
'' + ''
${text}
'';
checkPhase =
if checkPhase == null then ''
runHook preCheck
${stdenv.shellDryRun} "$target"
# use shellcheck which does not include docs
# pandoc takes long to build and documentation isn't needed for in nixpkgs usage
${lib.getExe (haskell.lib.compose.justStaticExecutables shellcheck.unwrapped)} "$target"
runHook postCheck
''
else checkPhase;
};
# Create a C binary
writeCBin = name: code:
runCommandCC name
{
inherit name code;
executable = true;
passAsFile = ["code"];
# Pointless to do this on a remote machine.
preferLocalBuild = true;
allowSubstitutes = false;
meta = {
mainProgram = name;
};
}
''
n=$out/bin/$name
mkdir -p "$(dirname "$n")"
mv "$codePath" code.c
$CC -x c code.c -o "$n"
'';
/* concat a list of files to the nix store.
The contents of files are added to the file in the store.
Example:
# Writes my-file to /nix/store/<store path>
concatTextFile {
name = "my-file";
files = [ drv1 "${drv2}/path/to/file" ];
}
See also the `concatText` helper function below.
# Writes executable my-file to /nix/store/<store path>/bin/my-file
concatTextFile {
name = "my-file";
files = [ drv1 "${drv2}/path/to/file" ];
executable = true;
destination = "/bin/my-file";
}
*/
concatTextFile =
{ name # the name of the derivation
, files
, executable ? false # run chmod +x ?
, destination ? "" # relative path appended to $out eg "/bin/foo"
, checkPhase ? "" # syntax checks, e.g. for scripts
, meta ? { }
}:
runCommandLocal name
{ inherit files executable checkPhase meta destination; }
''
file=$out$destination
mkdir -p "$(dirname "$file")"
cat $files > "$file"
if [ -n "$executable" ]; then
chmod +x "$file"
fi
eval "$checkPhase"
'';
/*
Writes a text file to nix store with no optional parameters available.
Example:
# Writes contents of files to /nix/store/<store path>
concatText "my-file" [ file1 file2 ]
*/
concatText = name: files: concatTextFile { inherit name files; };
/*
Writes a text file to nix store with and mark it as executable.
Example:
# Writes contents of files to /nix/store/<store path>
concatScript "my-file" [ file1 file2 ]
*/
concatScript = name: files: concatTextFile { inherit name files; executable = true; };
/*
Create a forest of symlinks to the files in `paths'.
This creates a single derivation that replicates the directory structure
of all the input paths.
BEWARE: it may not "work right" when the passed paths contain symlinks to directories.
Example:
# adds symlinks of hello to current build.
symlinkJoin { name = "myhello"; paths = [ pkgs.hello ]; }
# adds symlinks of hello and stack to current build and prints "links added"
symlinkJoin { name = "myexample"; paths = [ pkgs.hello pkgs.stack ]; postBuild = "echo links added"; }
This creates a derivation with a directory structure like the following:
/nix/store/sglsr5g079a5235hy29da3mq3hv8sjmm-myexample
|-- bin
| |-- hello -> /nix/store/qy93dp4a3rqyn2mz63fbxjg228hffwyw-hello-2.10/bin/hello
| `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/bin/stack
`-- share
|-- bash-completion
| `-- completions
| `-- stack -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/bash-completion/completions/stack
|-- fish
| `-- vendor_completions.d
| `-- stack.fish -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1/share/fish/vendor_completions.d/stack.fish
...
symlinkJoin and linkFarm are similar functions, but they output
derivations with different structure.
symlinkJoin is used to create a derivation with a familiar directory
structure (top-level bin/, share/, etc), but with all actual files being symlinks to
the files in the input derivations.
symlinkJoin is used many places in nixpkgs to create a single derivation
that appears to contain binaries, libraries, documentation, etc from
multiple input derivations.
linkFarm is instead used to create a simple derivation with symlinks to
other derivations. A derivation created with linkFarm is often used in CI
as a easy way to build multiple derivations at once.
*/
symlinkJoin =
args_@{ name
, paths
, preferLocalBuild ? true
, allowSubstitutes ? false
, postBuild ? ""
, ...
}:
let
args = removeAttrs args_ [ "name" "postBuild" ]
// {
inherit preferLocalBuild allowSubstitutes;
passAsFile = [ "paths" ];
}; # pass the defaults
in runCommand name args
''
mkdir -p $out
for i in $(cat $pathsPath); do
${lndir}/bin/lndir -silent $i $out
done
${postBuild}
'';
/*
Quickly create a set of symlinks to derivations.
This creates a simple derivation with symlinks to all inputs.
entries can be a list of attribute sets like
[ { name = "name" ; path = "/nix/store/..."; } ]
or an attribute set name -> path like:
{ name = "/nix/store/..."; other = "/nix/store/..."; }
Example:
# Symlinks hello and stack paths in store to current $out/hello-test and
# $out/foobar.
linkFarm "myexample" [ { name = "hello-test"; path = pkgs.hello; } { name = "foobar"; path = pkgs.stack; } ]
This creates a derivation with a directory structure like the following:
/nix/store/qc5728m4sa344mbks99r3q05mymwm4rw-myexample
|-- foobar -> /nix/store/6lzdpxshx78281vy056lbk553ijsdr44-stack-2.1.3.1
`-- hello-test -> /nix/store/qy93dp4a3rqyn2mz63fbxjg228hffwyw-hello-2.10
See the note on symlinkJoin for the difference between linkFarm and symlinkJoin.
*/
linkFarm = name: entries:
let
entries' =
if (lib.isAttrs entries) then entries
# We do this foldl to have last-wins semantics in case of repeated entries
else if (lib.isList entries) then lib.foldl (a: b: a // { "${b.name}" = b.path; }) { } entries
else throw "linkFarm entries must be either attrs or a list!";
linkCommands = lib.mapAttrsToList (name: path: ''
mkdir -p "$(dirname ${lib.escapeShellArg "${name}"})"
ln -s ${lib.escapeShellArg "${path}"} ${lib.escapeShellArg "${name}"}
'') entries';
in
runCommand name {
preferLocalBuild = true;
allowSubstitutes = false;
passthru.entries = entries';
} ''
mkdir -p $out
cd $out
${lib.concatStrings linkCommands}
'';
/*
Easily create a linkFarm from a set of derivations.
This calls linkFarm with a list of entries created from the list of input
derivations. It turns each input derivation into an attribute set
like { name = drv.name ; path = drv }, and passes this to linkFarm.
Example:
# Symlinks the hello, gcc, and ghc derivations in $out
linkFarmFromDrvs "myexample" [ pkgs.hello pkgs.gcc pkgs.ghc ]
This creates a derivation with a directory structure like the following:
/nix/store/m3s6wkjy9c3wy830201bqsb91nk2yj8c-myexample
|-- gcc-wrapper-9.2.0 -> /nix/store/fqhjxf9ii4w4gqcsx59fyw2vvj91486a-gcc-wrapper-9.2.0
|-- ghc-8.6.5 -> /nix/store/gnf3s07bglhbbk4y6m76sbh42siym0s6-ghc-8.6.5
`-- hello-2.10 -> /nix/store/k0ll91c4npk4lg8lqhx00glg2m735g74-hello-2.10
*/
linkFarmFromDrvs = name: drvs:
let mkEntryFromDrv = drv: { name = drv.name; path = drv; };
in linkFarm name (map mkEntryFromDrv drvs);
# docs in doc/builders/special/makesetuphook.section.md
makeSetupHook =
{ name ? lib.warn "calling makeSetupHook without passing a name is deprecated." "hook"
, deps ? [ ]
# hooks go in nativeBuildInput so these will be nativeBuildInput
, propagatedBuildInputs ? [ ]
# these will be buildInputs
, depsTargetTargetPropagated ? [ ]
, meta ? { }
, passthru ? { }
, substitutions ? { }
}:
script:
runCommand name
(substitutions // {
# TODO(@Artturin:) substitutions should be inside the env attrset
# but users are likely passing non-substitution arguments through substitutions
# turn off __structuredAttrs to unbreak substituteAll
__structuredAttrs = false;
inherit meta;
inherit depsTargetTargetPropagated;
propagatedBuildInputs =
# remove list conditionals before 23.11
lib.warnIf (!lib.isList deps) "'deps' argument to makeSetupHook must be a list. content of deps: ${toString deps}"
(lib.warnIf (deps != [ ]) "'deps' argument to makeSetupHook is deprecated and will be removed in release 23.11., Please use propagatedBuildInputs instead. content of deps: ${toString deps}"
propagatedBuildInputs ++ (if lib.isList deps then deps else [ deps ]));
strictDeps = true;
# TODO 2023-01, no backport: simplify to inherit passthru;
passthru = passthru
// optionalAttrs (substitutions?passthru)
(warn "makeSetupHook (name = ${lib.strings.escapeNixString name}): `substitutions.passthru` is deprecated. Please set `passthru` directly."
substitutions.passthru);
})
(''
mkdir -p $out/nix-support
cp ${script} $out/nix-support/setup-hook
recordPropagatedDependencies
'' + lib.optionalString (substitutions != {}) ''
substituteAll ${script} $out/nix-support/setup-hook
'');
# Write the references (i.e. the runtime dependencies in the Nix store) of `path' to a file.
writeReferencesToFile = path: runCommand "runtime-deps"
{
exportReferencesGraph = ["graph" path];
}
''
touch $out
while read path; do
echo $path >> $out
read dummy
read nrRefs
for ((i = 0; i < nrRefs; i++)); do read ref; done
done < graph
'';
/*
Write the set of references to a file, that is, their immediate dependencies.
This produces the equivalent of `nix-store -q --references`.
*/
writeDirectReferencesToFile = path: runCommand "runtime-references"
{
exportReferencesGraph = ["graph" path];
inherit path;
}
''
touch ./references
while read p; do
read dummy
read nrRefs
if [[ $p == $path ]]; then
for ((i = 0; i < nrRefs; i++)); do
read ref;
echo $ref >>./references
done
else
for ((i = 0; i < nrRefs; i++)); do
read ref;
done
fi
done < graph
sort ./references >$out
'';
/*
Extract a string's references to derivations and paths (its
context) and write them to a text file, removing the input string
itself from the dependency graph. This is useful when you want to
make a derivation depend on the string's references, but not its
contents (to avoid unnecessary rebuilds, for example).
Note that this only works as intended on Nix >= 2.3.
*/
writeStringReferencesToFile = string:
/*
The basic operation this performs is to copy the string context
from `string' to a second string and wrap that string in a
derivation. However, that alone is not enough, since nothing in the
string refers to the output paths of the derivations/paths in its
context, meaning they'll be considered build-time dependencies and
removed from the wrapper derivation's closure. Putting the
necessary output paths in the new string is however not very
straightforward - the attrset returned by `getContext' contains
only references to derivations' .drv-paths, not their output
paths. In order to "convert" them, we try to extract the
corresponding paths from the original string using regex.
*/
let
# Taken from https://github.com/NixOS/nix/blob/130284b8508dad3c70e8160b15f3d62042fc730a/src/libutil/hash.cc#L84
nixHashChars = "0123456789abcdfghijklmnpqrsvwxyz";
context = builtins.getContext string;
derivations = lib.filterAttrs (n: v: v ? outputs) context;
# Objects copied from outside of the store, such as paths and
# `builtins.fetch*`ed ones
sources = lib.attrNames (lib.filterAttrs (n: v: v ? path) context);
packages =
lib.mapAttrs'
(name: value:
{
inherit value;
name = lib.head (builtins.match "${builtins.storeDir}/[${nixHashChars}]+-(.*)\.drv" name);
})
derivations;
# The syntax of output paths differs between outputs named `out`
# and other, explicitly named ones. For explicitly named ones,
# the output name is suffixed as `-name`, but `out` outputs
# aren't suffixed at all, and thus aren't easily distinguished
# from named output paths. Therefore, we find all the named ones
# first so we can use them to remove false matches when looking
# for `out` outputs (see the definition of `outputPaths`).
namedOutputPaths =
lib.flatten
(lib.mapAttrsToList
(name: value:
(map
(output:
lib.filter
lib.isList
(builtins.split "(${builtins.storeDir}/[${nixHashChars}]+-${name}-${output})" string))
(lib.remove "out" value.outputs)))
packages);
# Only `out` outputs
outputPaths =
lib.flatten
(lib.mapAttrsToList
(name: value:
if lib.elem "out" value.outputs then
lib.filter
(x: lib.isList x &&
# If the matched path is in `namedOutputPaths`,
# it's a partial match of an output path where
# the output name isn't `out`
lib.all (o: !lib.hasPrefix (lib.head x) o) namedOutputPaths)
(builtins.split "(${builtins.storeDir}/[${nixHashChars}]+-${name})" string)
else
[])
packages);
allPaths = lib.concatStringsSep "\n" (lib.unique (sources ++ namedOutputPaths ++ outputPaths));
allPathsWithContext = builtins.appendContext allPaths context;
in
if builtins ? getContext then
writeText "string-references" allPathsWithContext
else
writeDirectReferencesToFile (writeText "string-file" string);
/* Print an error message if the file with the specified name and
hash doesn't exist in the Nix store. This function should only
be used by non-redistributable software with an unfree license
that we need to require the user to download manually. It produces
packages that cannot be built automatically.
Example:
requireFile {
name = "my-file";
url = "http://example.com/download/";
sha256 = "ffffffffffffffffffffffffffffffffffffffffffffffffffff";
}
*/
requireFile = { name ? null
, sha256 ? null
, sha1 ? null
, hash ? null
, url ? null
, message ? null
, hashMode ? "flat"
} :
assert (message != null) || (url != null);
assert (sha256 != null) || (sha1 != null) || (hash != null);
assert (name != null) || (url != null);
let msg =
if message != null then message
else ''
Unfortunately, we cannot download file ${name_} automatically.
Please go to ${url} to download it yourself, and add it to the Nix store
using either
nix-store --add-fixed ${hashAlgo} ${name_}
or
nix-prefetch-url --type ${hashAlgo} file:///path/to/${name_}
'';
hashAlgo = if hash != null then (builtins.head (lib.strings.splitString "-" hash))
else if sha256 != null then "sha256"
else "sha1";
hashAlgo_ = if hash != null then "" else hashAlgo;
hash_ = if hash != null then hash
else if sha256 != null then sha256
else sha1;
name_ = if name == null then baseNameOf (toString url) else name;
in
stdenvNoCC.mkDerivation {
name = name_;
outputHashMode = hashMode;
outputHashAlgo = hashAlgo_;
outputHash = hash_;
preferLocalBuild = true;
allowSubstitutes = false;
builder = writeScript "restrict-message" ''
source ${stdenvNoCC}/setup
cat <<_EOF_
***
${msg}
***
_EOF_
exit 1
'';
};
/*
Copy a path to the Nix store.
Nix automatically copies files to the store before stringifying paths.
If you need the store path of a file, ${copyPathToStore <path>} can be
shortened to ${<path>}.
*/
copyPathToStore = builtins.filterSource (p: t: true);
/*
Copy a list of paths to the Nix store.
*/
copyPathsToStore = builtins.map copyPathToStore;
/* Applies a list of patches to a source directory.
Example:
# Patching nixpkgs:
applyPatches {
src = pkgs.path;
patches = [
(pkgs.fetchpatch {
url = "https://github.com/NixOS/nixpkgs/commit/1f770d20550a413e508e081ddc08464e9d08ba3d.patch";
sha256 = "1nlzx171y3r3jbk0qhvnl711kmdk57jlq4na8f8bs8wz2pbffymr";
})
];
}
*/
applyPatches =
{ src
, name ? (if builtins.typeOf src == "path"
then builtins.baseNameOf src
else
if builtins.isAttrs src && builtins.hasAttr "name" src
then src.name
else throw "applyPatches: please supply a `name` argument because a default name can only be computed when the `src` is a path or is an attribute set with a `name` attribute."
) + "-patched"
, patches ? []
, postPatch ? ""
}: stdenvNoCC.mkDerivation {
inherit name src patches postPatch;
preferLocalBuild = true;
allowSubstitutes = false;
phases = "unpackPhase patchPhase installPhase";
installPhase = "cp -R ./ $out";
};
/* An immutable file in the store with a length of 0 bytes. */
emptyFile = runCommand "empty-file" {
outputHashAlgo = "sha256";
outputHashMode = "recursive";
outputHash = "0ip26j2h11n1kgkz36rl4akv694yz65hr72q4kv4b3lxcbi65b3p";
preferLocalBuild = true;
} "touch $out";
/* An immutable empty directory in the store. */
emptyDirectory = runCommand "empty-directory" {
outputHashAlgo = "sha256";
outputHashMode = "recursive";
outputHash = "0sjjj9z1dhilhpc8pq4154czrb79z9cm044jvn75kxcjv6v5l2m5";
preferLocalBuild = true;
} "mkdir $out";
}