bug#65763: Error opening a file from a Git working directory if Git is not installed

[Eli Zaretskii]

> From: Paul Pogonyshev <pogonyshev@gmail.com>
> Date: Wed, 6 Sep 2023 09:29:59 +0200
> Cc: 65763@debbugs.gnu.org
> 
> The problem appears to be only with `debug-on-error'. However, there are 
> cases where you cannot
> control it at all, e.g. with ERT (probably also Buttercup or any other 
> testing framework). In effect, an
> ERT test fails for a "random" reason, depending on which machine it is 
> executed, i.e. it fails inside
> that Docker container.

I see.

Well, we could then protect the execution of the problematic form "by
hand" by using condition-case-unless-debug.  Dmitry, WDYT?