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

From: Eric Sunshine <sunshine@sunshineco.com>
Date: May 16, 2019, 23:16 UTC
Message-ID: <CAPig+cQQ5svrDKRPenL2+bJHGjddUPnAXCFSsQN+WBHqzGpDow@mail.gmail.com>
In-Reply-To: <20190516221702.GA11784@sigill.intra.peff.net>

On Thu, May 16, 2019 at 6:17 PM Jeff King <peff@peff.net> wrote:

Show 12 quoted lines

> 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?