bug: for-each-repo malfunctions in worktree due to GIT_DIR

I noticed some scripts I have that utilize `git for-each-repo` don't
work if I run them from within a git worktree, but they do work fine
from within other directories, including the parent git clone of those
worktrees. The symptom is that the command I pass to `for-each-repo`
is run as if from within the worktree each time, instead of the repos
fetched from the corresponding config entry.

After a bit of sleuthing with strace, I think I identified the cause:
$GIT_DIR is set in the `git for-each-repo` process, and gets passed to
the child git invocations it launches.

And thus, from within that worktree, `git for-each-repo
--config=foo.bar -- branch` becomes the equivalent of:

GIT_DIR=/worktree-parent/.git git -C /unrelated-repo branch

Which of course is not what the `for-each-repo` invocation would be
expected to do.

Observed with git 2.51.0 from Ubuntu 25.10. I haven't tested
explicitly with latest, but I took a quick look at git.c and
for-each-repo.c changes between there and master and didn't see
anything that looked like it would affect this behavior.

PS: please CC me on replies

On 2/23/26 5:58 PM, Matthew Gabeler-Lee wrote:

I noticed some scripts I have that utilize `git for-each-repo` don't
work if I run them from within a git worktree, but they do work fine
from within other directories, including the parent git clone of those
worktrees. The symptom is that the command I pass to `for-each-repo`
is run as if from within the worktree each time, instead of the repos
fetched from the corresponding config entry.

After a bit of sleuthing with strace, I think I identified the cause:
$GIT_DIR is set in the `git for-each-repo` process, and gets passed to
the child git invocations it launches.

And thus, from within that worktree, `git for-each-repo
--config=foo.bar -- branch` becomes the equivalent of:

GIT_DIR=/worktree-parent/.git git -C /unrelated-repo branch

Which of course is not what the `for-each-repo` invocation would be
expected to do.

You're absolutely right on this. It's a subtle oversight, as it's not
one of the worktree-specific variables, but GIT_DIR is being set by
the worktree logic.

I have a test and a fix on the way in [1]. You'll be CC'd when I send
the patches after a CI run.

[1] https://github.com/gitgitgadget/git/pull/2056

Thanks,
-Stolee