Re: Bug: `git init` with hook `reference-transaction` running `git rev-parse --git-dir` fails

From: Patrick Steinhardt <ps@pks.im>
Date: Oct 7, 2024, 11:24 UTC
Message-ID: <ZwPEwL-fKHBkUOcm@pks.im>
In-Reply-To: <a8807b44026458097267932f429ef61d5b77aa4c.camel@gmail.com>

On Mon, Oct 07, 2024 at 01:02:56PM +0200, Gabriel Nützi wrote:

> Ah, jeah thats true:
> 
> The command in question which is `git rev-parse --git-dir` to find the actual GIT_DIR is actually the issue here:
> It relies on having a proper HEAD despite the docs saying it only reports GIT_DIR if set etc...

That's not quite true. The second paragraph for the `--git-dir` option in git-rev-parse(1) has this to say:

    If $GIT_DIR is not defined and the current directory is not detected to lie in a Git
    repository or work tree print a message to stderr and exit with nonzero status.

But in our case you're correct: `$GIT_DIR` _is_ defined during hook execution. So in theory, if git-rev-parse(1) behaved exactly as documented, it shouldn't even care whether or not it is executing in a repository.

> Could we maybe make these commands more agnostic?

So this could indeed be a viable fix, but I guess we'd rather play whack-a-mole because other Git commands that one may want to execute in this repository would also be broken.

> Making an empty HEAD probably directly also resolves these commands to work correctly.

So agreed, creating a stub HEAD is the most sensible option we have. I'd like to wait a bit for more feedback from other contributors before we do so though.

Patrick