python3 spkg-configure.m4: Do not reject python based on sysconfig LDFLAGS containing "-L."

[mkoeppe]

(follow up from #31132)

gentoo appears to use this flag (as reported in https://groups.google.com/g/sage-release/c/hVIsURxpdhc/m/MS1Km9GHBAAJ), which is redundant but harmless.

CC: @strogdon

Component: build: configure

Author: Matthias Koeppe

Branch/Commit: 18a7d18

Reviewer: Steven Trogdon

Issue created by migration from https://trac.sagemath.org/ticket/31358

[mkoeppe]

Branch: u/mkoeppe/python3_spkg_configure_m4__do_not_reject_python_based_on_sysconfig_ldflags_containing___l__

[mkoeppe]

comment:3

According to tox -e docker-gentoo-standard -- config.status, this change fixes it.

---

New commits:

18a7d18

build/pkgs/python3/spkg-configure.m4: -L. and -I. are OK

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Commit: 18a7d18

[strogdon]

comment:4

I still see the issue here

#! git log
commit 18a7d183983b5f4a8153cb2066624fa74ad49814 (HEAD -> trac_31358, trac/u/mkoeppe/python3_spkg_configure_m4__do_not_reject_python_based_on_sysconfig_ldflags_containing___l__)
Author: Matthias Koeppe <mkoeppe@math.ucdavis.edu>
Date:   Sun Feb 7 21:23:46 2021 -0800

    build/pkgs/python3/spkg-configure.m4: -L. and -I. are OK

commit 8453ffb849b047893b6c61dd09176a84c9133342 (tag: 9.3.beta7, origin/develop, origin/HEAD, develop)
Author: Release Manager <release@sagemath.org>
Date:   Sun Feb 7 20:42:26 2021 +0100

    Updated SageMath version to 9.3.beta7

commit 6096110e060e441df3219fd8caef1c4525145983
Merge: e67fc51749 c40efe9f4b
Author: Release Manager <release@sagemath.org>
Date:   Sun Feb 7 12:55:53 2021 +0100

    Trac #30517: MemoryError in doctesting combinat/designs/gen_quadrangles_with_spread.pyx

and after either ./configure or ./configure --with-system-python3=yes I have

x86_64-pc-linux-gnu-g++ -pthread -shared -Wl,-O1 -Wl,--as-needed conftest.dir/temp.linux-x86_64-3.9/conftest.o -L/usr/lib64 -o conftest.dir/lib.linux-x86_64-3.9/config_check_distutils_cxx.cpython-39-x86_64-linux-gnu.so
        LDFLAGS = "-Wl,-O1 -Wl,--as-needed -L."
configure:32030: result: no, this is a misconfigured Python whose sysconfig compiler/linker flags contain -I or -L options, which may cause wrong versions of libraries to leak into the build of Python packages - see https://github.com/sagemath/sage-prod/issues/31132; to use it anyway, use ./configure --with-python=/usr/bin/python3

[mkoeppe]

comment:5

Did you run ./bootstrap?

[strogdon]

comment:6

Replying to @mkoeppe:

Did you run ./bootstrap?

That was it.

configure:39140: result: python3-3.9.1:                               using system package; SPKG will not be installed

Thanks

[strogdon]

Reviewer: Steven Trogdon

[mkoeppe]

comment:7

Thanks for testing!

[vbraun]

Changed branch from u/mkoeppe/python3_spkg_configure_m4__do_not_reject_python_based_on_sysconfig_ldflags_containing___l__ to 18a7d18