This option isn't available on slightly older versions of git. We were
no longer using the real describe functionality anyway, so let's just do
something simpler to detect a dirty worktree.
While we're here, fix up a little bit of sh style.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
The output of `wc -l` on darwin starts with a tab:
git rev-list 266f6548611ad0de93e7470eb13731db819f184b..HEAD | wc -l
0
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
git worktrees have a .git file rather than a .git directory, so building
in a worktree caused version.sh to generate an error.
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>