[PATCH] Implement run-built-tests=no for make xcheck

[Florian Weimer]

* Andreas K. Huettel:

> Am Donnerstag, 19. September 2024, 15:53:23 MESZ schrieb Florian Weimer:
>> Previously, the second occurrence of the xtests target
>> expected all xtests to run (as the r esult of specifying
>> $(xtests)), but these tests have not been run due to
>> the the first xtests target is set up in run-built-tests=no:
>> it only runs tests in $(xtests-special).
>> 
>> To make run-built-tests=no actually useful, tweak the
>> first xtests target to build tests, similar to what the
>> parallel tests target does.
>> 
>
> More general question in this context:
>
> I have been assuming that "make xcheck" is deprecated and should not be 
> used anymore. Following Carlos' lead, I have consequently also removed
> mentions of xcheck from our wiki.
>
> * Is this incorrect and is xcheck still actively in use?

I've recently added xcheck tests.  I wasn't aware that there was an
effort to remove them.  We have xtests that should be deleted
(nss/bug-erange for example, because we have equivalent/better coverage
in other tests), or that could be converted to one or two regular tests
(with the special one automatically marked as unsupported).  Some
previously destructive tests can be carried out in namespaces today
(e.g., testing sethostname).

> * If not, shouldn't it rather fully go away then?

I don't think they can fully go away, ever.  If we have tests that take
minutes to run even on fast/large systems, we don't want them to run
during make check.  It's not useful to stretch testing time from less
than 15 minutes to more than half an hour without a substantial increase
in coverage.

Thanks,
Florian