Re: Running 'git worktree add' in 'pre-commit' hook

[Jeff King <peff@peff.net>]

On Thu, May 16, 2019 at 07:16:54PM -0400, Eric Sunshine wrote:

> On Thu, May 16, 2019 at 6:17 PM Jeff King <peff@peff.net> wrote:
> > On Thu, May 16, 2019 at 06:25:24PM +0700, Duy Nguyen wrote:
> > > So you probably can still make it work by backing up $GIT_INDEX_FILE
> > > (in case you need it), then unset it before you use "git worktree" (or
> > > cd to it if you keep a permanent separate worktree for pre-commit
> > > activities). [...]
> >
> > The case of actually _adding_ a new work tree (before we enter it) is
> > weirder, though. We definitely want to stay in the same repository, and
> > clearing all of that would not make sense. I do wonder if worktree-add
> > should be handling GIT_INDEX_FILE (ignoring it when we want to be
> > dealing with the index of the new worktree we added, and handling any
> > relative fixups if we chdir inside the worktree code).
> 
> Ignoring GIT_INDEX_FILE was indeed the conclusion reached earlier in
> this thread. Addressing your other point, "git worktree add" does
> chdir() into the new worktree if a post-checkout hook exists since
> that hook needs to run in the new worktree, not in the worktree in
> which the "git worktree add" command itself was invoked. For the hook
> invocation, it already sanitizes the environment of GIT_DIR and
> GIT_WORK_TREE, and GIT_INDEX_FILE ought to be cleaned too. Is there
> any existing code in Git for doing the relative fixups you mention for
> other Git environment variables?

You can assign local_repo_env to child_process.env (or push it
individually to env_array if you have to mix with other variables). See
git_connect() for an example.

-Peff