nixpkgs/pkgs/build-support/mkshell/default.nix
Linus Heckemann c4b83df38a mkShell: set preferLocalBuild by default
Before this change, `nix develop` would often result in all the
shell's dependencies being copied to a remote builder, only for the
remote builder to run a trivial derivation build. This change makes
`nix develop` much faster on systems with remote builders configured.
2023-02-22 11:53:51 +01:00

59 lines
1.6 KiB
Nix

{ lib, stdenv, buildEnv }:
# A special kind of derivation that is only meant to be consumed by the
# nix-shell.
{ name ? "nix-shell"
, # a list of packages to add to the shell environment
packages ? [ ]
, # propagate all the inputs from the given derivations
inputsFrom ? [ ]
, buildInputs ? [ ]
, nativeBuildInputs ? [ ]
, propagatedBuildInputs ? [ ]
, propagatedNativeBuildInputs ? [ ]
, ...
}@attrs:
let
mergeInputs = name:
(attrs.${name} or [ ]) ++
(lib.subtractLists inputsFrom (lib.flatten (lib.catAttrs name inputsFrom)));
rest = builtins.removeAttrs attrs [
"name"
"packages"
"inputsFrom"
"buildInputs"
"nativeBuildInputs"
"propagatedBuildInputs"
"propagatedNativeBuildInputs"
"shellHook"
];
in
stdenv.mkDerivation ({
inherit name;
buildInputs = mergeInputs "buildInputs";
nativeBuildInputs = packages ++ (mergeInputs "nativeBuildInputs");
propagatedBuildInputs = mergeInputs "propagatedBuildInputs";
propagatedNativeBuildInputs = mergeInputs "propagatedNativeBuildInputs";
shellHook = lib.concatStringsSep "\n" (lib.catAttrs "shellHook"
(lib.reverseList inputsFrom ++ [ attrs ]));
phases = [ "buildPhase" ];
buildPhase = ''
{ echo "------------------------------------------------------------";
echo " WARNING: the existence of this path is not guaranteed.";
echo " It is an internal implementation detail for pkgs.mkShell.";
echo "------------------------------------------------------------";
echo;
# Record all build inputs as runtime dependencies
export;
} >> "$out"
'';
preferLocalBuild = true;
} // rest)