>> The call to spawn clears the environment, including PATH.  This means
>> that an env in a non-default location wouldn't be found, while all the
>> other tests work because they use PATH.  We can fix this by looking up
>> which PATH to use beforehand.
>
> Thanks for reporting this issue, but... is that it?
> We also use spawn() for 'git', among other things...

Yes, I can confirm that this was the only failing test case in my build.
(It may be of note however that I did not have Xapian enabled.  Trying
to build with that caused a host of other failures that were beyond my
ability to troubleshoot, so I decided to just give up on running the
tests for now, since they seem very dependent on the environment and the
environment inside our build sandboxes is so different from what
public-inbox will have on a running system anyway.)

> For the pure Perl codepath, this ought to be a more encompassing
> alternative to your patch:
>
> [ ... snip ... ]
>
> Can you confirm?  Thanks.

I can confirm that this patch also solves my problem.  Thank you very
much.