1
0
Fork 1
mirror of https://github.com/NixOS/nixpkgs.git synced 2024-11-18 11:40:45 +00:00
nixpkgs/pkgs/build-support/closure-info.nix
Linus Heckemann bdd23d10b2 closureInfo: handle empty path set explicitly
Arguably, this is a bug in Nix's structuredAttrs: without
structuredAttrs, exportReferencesGraph with an empty path set would
still result in information being provided. With structuredAttrs, no
info is provided for an empty path set.

Nevertheless, we need to be able to build even if Nix has the bug, so
work around it by checking for an empty path set and handling it
explicitly.
2023-11-04 09:54:41 +01:00

43 lines
1.1 KiB
Nix

# This derivation builds two files containing information about the
# closure of 'rootPaths': $out/store-paths contains the paths in the
# closure, and $out/registration contains a file suitable for use with
# "nix-store --load-db" and "nix-store --register-validity
# --hash-given".
{ stdenv, coreutils, jq }:
{ rootPaths }:
assert builtins.langVersion >= 5;
stdenv.mkDerivation {
name = "closure-info";
__structuredAttrs = true;
exportReferencesGraph.closure = rootPaths;
preferLocalBuild = true;
nativeBuildInputs = [ coreutils jq ];
empty = rootPaths == [];
buildCommand =
''
out=''${outputs[out]}
mkdir $out
if [[ -n "$empty" ]]; then
echo 0 > $out/total-nar-size
touch $out/registration $out/store-paths
else
jq -r ".closure | map(.narSize) | add" < "$NIX_ATTRS_JSON_FILE" > $out/total-nar-size
jq -r '.closure | map([.path, .narHash, .narSize, "", (.references | length)] + .references) | add | map("\(.)\n") | add' < "$NIX_ATTRS_JSON_FILE" | head -n -1 > $out/registration
jq -r '.closure[].path' < "$NIX_ATTRS_JSON_FILE" > $out/store-paths
fi
'';
}