Subject: Re: Running git(1) from within hooks/post-update

From: Alejandro Colomar <[email-masked]>
Date: Fri, 24 Nov 2023 16:49:05 +0100

On Fri, Nov 24, 2023 at 04:42:16PM +0100, Alejandro Colomar wrote:
> On Fri, Nov 24, 2023 at 03:00:22PM +0100, Alejandro Colomar wrote:
> > Hi,
> > 
> > I'm trying to set up a post-update hook to produce a build of the Linux
> > man-pages PDF book after every push to my personal server to the 'main'
> > branch, so that I can serve man-pages-HEAD.pdf at some URL, for users to
> > be able to easily check the manual at git HEAD without having to clone
> > the repo.
> > 
> > I thought of having a git non-bare repo where I build it, so the script
> > would be the following (the paths are tmp, because I'm still testing).
> > 
> > 	$ cat post-update 
> > 	#!/bin/sh
> > 
> > 	test "$1" = "refs/heads/main" || exit 0;
> > 
> > 	cd ~/tmp/man-pages/;
> > 
> > 	whoami; pwd; ls -ld .git/;  # This is for debugging.
> > 
> > 	git fetch srv			#>/dev/null 2>&1;
> > 	git reset srv/main --hard	#>/dev/null 2>&1;
> > 	git clean -dffx			#>/dev/null 2>&1;
> > 	scripts/LinuxManBook/build.sh	>~/tmp/LMB-HEAD.pdf &
> 
> The script works fine when called manually.  It seems it's calling it
> as a hook that fails.  It seems it's running git(1) from within a
> post-update hook that is problematic.  Is that expected, or is it a bug,
> and can it be fixed?

Ahh, after this I've found it documented in githooks(5):

     Environment variables, such as GIT_DIR, GIT_WORK_TREE, etc., are
     exported so that Git commands run by the hook can correctly
     locate the repository. If your hook needs to invoke Git commands
     in a foreign repository or in a different working tree of the
     same repository, then it should clear these environment variables
     so they do not interfere with Git operations at the foreign
     location. For example:

         local_desc=$(git describe)
         foreign_desc=$(unset $(git rev-parse --local-env-vars); git -C ../foreign-repo describe)

Never mind.

Thanks,
Alex

> 
> > 
> > But it's not working.  The git(1) calls are failing, saying it's not a
> > git repo, but it clearly is, and I have permissions, so I don't
> > understand what's going wrong.  Here's the 'remote:' output of a push to
> > that testing server:
> > 
> > 	remote: alx
> > 	remote: /home/alx/tmp/man-pages
> > 	remote: drwxr-xr-x 8 alx alx 4096 Nov 24 14:41 .git/
> > 	remote: fatal: not a git repository: '.'
> > 	remote: fatal: not a git repository: '.'
> > 	remote: fatal: not a git repository: '.'
> > 	remote: hooks/post-update: 12: ./scripts/LinuxManBook/build.sh: not found
> > 
> > Can you please help?  :)
> > 
> > Thanks,
> > Alex
> > 
> > -- 
> > <https://www.alejandro-colomar.es/>
> 
> 
> 
> -- 
> <https://www.alejandro-colomar.es/>

-- 
<https://www.alejandro-colomar.es/>