nixpkgs/pkgs/build-support/fetchgitlocal/default.nix
John Ericson 72660409f5 Rewrite fetchgitLocal
For practical purposes, here are the changes in behavior:
 - When fetching from a subdirectory of a repo, do not rebuild because of
   changes elsewhere in the repo
 - Fetch (not-ignored) untracked files too

It does this by letting git hash and export the directory in question,
which I believes makes for a cleaner implementation than the ad-hoc copying
and hashing that was there before.
2015-10-01 22:00:44 -07:00

40 lines
1.1 KiB
Nix

{ runCommand, git, nix }: src:
let
srcStr = toString src;
# Adds the current directory (respecting ignored files) to the git store, and returns the hash
gitHashFile = runCommand "put-in-git" {
nativeBuildInputs = [ git ];
dummy = builtins.currentTime; # impure, do every time
preferLocalBuild = true;
} ''
cd ${srcStr}
ROOT=$(git rev-parse --show-toplevel) # path to repo
cp $ROOT/.git/index $ROOT/.git/index-user # backup index
git reset # reset index
git add . # add current directory
# hash of current directory
# remove trailing newline
git rev-parse $(git write-tree) \
| tr -d '\n' > $out
mv $ROOT/.git/index-user $ROOT/.git/index # restore index
'';
gitHash = builtins.readFile gitHashFile; # cache against git hash
nixPath = runCommand "put-in-nix" {
nativeBuildInputs = [ git ];
preferLocalBuild = true;
} ''
mkdir $out
# dump tar of *current directory* at given revision
git -C ${srcStr} archive --format=tar ${gitHash} \
| tar xvf - -C $out
'';
in nixPath