Re: Test parallelism with CMake

[Liliana Marie Prikler]

Hi Greg,

Am Mittwoch, den 03.11.2021, 10:47 -0400 schrieb Greg Hogan:
> If the default is to disable parallel tests then it is unlikely that
> future committers will be aware of, remember, and bother to enable
> the setting. And once packages do override the default then there
> would be additional future work to invert the default value.
I don't think it'd be that bad.  It'd just be a case of counting how
many packages do what, announcing the change and going through a c-u
cycle.

> I do not know how to obtain the list of packages using the cmake-
> build-system.
Grep is a good approximation, but you can iterate over all packages and
check.

> The strategy looks to require multiple stages. First build and test
> the packages and ignore current failures. As noted by Liliana, next
> build and test the successful builds with ctest in serial. Hopefully
> no or few builds are newly failing at this point. Lastly build and
> test with ctest in parallel, and explicitly disable test parallelism
> for the failing builds.
I think you can skip check two if you've independently verified for a
given package, that parallel ctest works.  What we would have to verify
now is whether indeed all (but perhaps a tiny minority of) cmake
packages test with ctest.

Cheers