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.
This commit is contained in:
John Ericson 2015-10-01 21:58:24 -07:00
parent e916273209
commit 72660409f5

View file

@ -1,23 +1,40 @@
{ runCommand, git, nix }: src:
let hash = import (runCommand "head-hash.nix"
{ dummy = builtins.currentTime;
preferLocalBuild = true; }
''
cd ${toString src}
(${git}/bin/git show && ${git}/bin/git diff) > $out
hash=$(${nix}/bin/nix-hash $out)
echo "\"$hash\"" > $out
''); in
let
srcStr = toString src;
runCommand "local-git-export"
{ dummy = hash;
preferLocalBuild = true; }
''
cd ${toString src}
mkdir -p "$out"
for file in $(${git}/bin/git ls-files); do
mkdir -p "$out/$(dirname $file)"
cp -d $file "$out/$file" || true # don't fail when trying to copy a directory
done
''
# 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