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

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 &

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