Detect and use the system fflas-ffpack

[orlitzky]

This package already has an spkg-configure.m4 file and some distro information, but we can't yet detect and use the system copy. Here's hoping everyone ships the pkg-config file.

CC: @embray @dimpase @mkoeppe @kiwifb

Component: build: configure

Author: Michael Orlitzky

Branch/Commit: bdac4ba

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/29453

[orlitzky]

Commit: 5ce8498

[orlitzky]

Branch: u/mjo/ticket/29453

[orlitzky]

comment:1

Here's a go at this. I picked the lower version bound based on what Debian has on repology.

---

New commits:

4cada3f	Trac #29453: use PKG_CHECK_MODULES to find a system fflas-ffpack.
5ce8498	Trac #29453: add Gentoo package information for fflas-ffpack.

[orlitzky]

comment:2

Eh, I see what's going on with the MP library stuff. Sage is installing MPIR but with everything named "gmp", so having the mpir SPKG installed does satisfy a "gmp" dependency. I'll have to add mpir to the DEPCHECK.

[orlitzky]

comment:3

Oh, I accidentally got this one right.

[mkoeppe]

comment:4

"Warning: this doesn't get executed with --without-system-fflas-ffpack"
... can this be fixed?