lib.fileset.gitTracked: Allow clones of shallow repositories

The only reason shallow clones are not the default in
`builtins.fetchGit` is that `revCount` can't be provided when cloning a
shallow repository. However, `revCount` isn't used or exposed by
`lib.fileset`. Hence, allowing cloning shallow repositories makes
`gitTracked` more general without any drawbacks.

Co-authored-by: Silvan Mosberger <github@infinisil.com>
This commit is contained in:
ibbem 2024-01-30 17:55:30 +01:00
parent d3c09ae008
commit 6558e89177
2 changed files with 31 additions and 1 deletions

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@ -5,6 +5,7 @@ let
isAttrs
isPath
isString
nixVersion
pathExists
readDir
split
@ -17,6 +18,7 @@ let
attrNames
attrValues
mapAttrs
optionalAttrs
zipAttrsWith
;
@ -56,6 +58,7 @@ let
substring
stringLength
hasSuffix
versionAtLeast
;
inherit (lib.trivial)
@ -840,6 +843,10 @@ rec {
# https://github.com/NixOS/nix/commit/55cefd41d63368d4286568e2956afd535cb44018
_fetchGitSubmodulesMinver = "2.4";
# Support for `builtins.fetchGit` with `shallow = true` was introduced in 2.4
# https://github.com/NixOS/nix/commit/d1165d8791f559352ff6aa7348e1293b2873db1c
_fetchGitShallowMinver = "2.4";
# Mirrors the contents of a Nix store path relative to a local path as a file set.
# Some notes:
# - The store path is read at evaluation time.
@ -894,7 +901,17 @@ rec {
# However a simpler alternative still would be [a builtins.gitLsFiles](https://github.com/NixOS/nix/issues/2944).
fetchResult = fetchGit ({
url = path;
} // extraFetchGitAttrs);
}
# In older Nix versions, repositories were always assumed to be deep clones, which made `fetchGit` fail for shallow clones
# For newer versions this was fixed, but the `shallow` flag is required.
# The only behavioral difference is that for shallow clones, `fetchGit` doesn't return a `revCount`,
# which we don't need here, so it's fine to always pass it.
# Unfortunately this means older Nix versions get a poor error message for shallow repositories, and there's no good way to improve that.
# Checking for `.git/shallow` doesn't seem worth it, especially since that's more of an implementation detail,
# and would also require more code to handle worktrees where `.git` is a file.
// optionalAttrs (versionAtLeast nixVersion _fetchGitShallowMinver) { shallow = true; }
// extraFetchGitAttrs);
in
# We can identify local working directories by checking for .git,
# see https://git-scm.com/docs/gitrepository-layout#_description.

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@ -1439,6 +1439,19 @@ if [[ -n "$fetchGitSupportsSubmodules" ]]; then
fi
rm -rf -- *
# shallow = true is not supported on all Nix versions
# and older versions don't support shallow clones at all
if [[ "$(nix-instantiate --eval --expr "$prefixExpression (versionAtLeast builtins.nixVersion _fetchGitShallowMinver)")" == true ]]; then
createGitRepo full
# Extra commit such that there's a commit that won't be in the shallow clone
git -C full commit --allow-empty -q -m extra
git clone -q --depth 1 "file://${PWD}/full" shallow
cd shallow
checkGitTracked
cd ..
rm -rf -- *
fi
# Go through all stages of Git files
# See https://www.git-scm.com/book/en/v2/Git-Basics-Recording-Changes-to-the-Repository