[petsc-dev] [Suggestion] Configure QOL Improvements

[Jed Brown]

Matthew Knepley <knepley at gmail.com> writes:

> On Wed, Oct 23, 2019 at 2:27 PM Jed Brown <jed at jedbrown.org> wrote:
>
>> Matthew Knepley via petsc-dev <petsc-dev at mcs.anl.gov> writes:
>>
>> > On Wed, Oct 23, 2019 at 11:24 AM Faibussowitsch, Jacob via petsc-dev <
>> > petsc-dev at mcs.anl.gov> wrote:
>> >> As I am largely unfamiliar with the internals of the configure process,
>> >> this is potentially more of an involved change than I am imagining,
>> given
>> >> that many libraries likely have many small dependencies and hooks which
>> >> have to be set throughout the configuration process, and so its possible
>> >> not everything could be skipped.
>> >>
>> >
>> > We had this many years ago. It was removed because the benefits did not
>> > outweigh the costs.
>>
>> I don't know if it's still the case, but it should be possible to run
>> non-interactively (like apt-get -y).  My bigger complaint is that
>> missing dependencies aren't resolved in the first couple seconds.
>>
>
> How do you know that you actually have something until you actually
> run the tests? This is the classic misconception of pkg-config, "I'll
> just believe the user", which generated 99% of user mail over the
> first 20 years of PETSc.

All other build systems get this right.  You're asking to build X and Y,
where Y depends on Z, and there is no --download-Z or --with-Z.  You
shouldn't need to build X before noticing that Z is unavailable.