spkg-configure for singular

[gh-thierry-FreeBSD]

In order to use a system package of singular (see #27330 ), I added a basic spkg-configure.m4.

[gh-thierry-FreeBSD]

spkg-configure.m4 for singular

[gh-thierry-FreeBSD]

With the attached file put under build/pkgs/singular configure works:

---

Checking whether SageMath should install SPKG singular...

checking whether any of gmp mpfr is installed or will be installed as SPKG... no

checking for libSingular... yes

configure: will use system package and not install SPKG singular

---

...

singular-4.1.1p2.p0: using system package; SPKG will not be installed

But I have remarked that sage builts only when singular has been built with '--with-ntl': some more checks could be added.

[gh-thierry-FreeBSD]

And after the build, with the system package, the error already reported in #22175 (freegb.lib not found) occurs (but certainly for another cause):

[dochtml] Build finished. The built documents can be found in /usr/ports/math/sage/work/stage/usr/local/share/doc/sage/inventory/en/reference/tensor_free_modules

[dochtml] Error building the documentation.

[dochtml] Traceback (most recent call last):

[dochtml] File "/usr/local/lib/python3.7/runpy.py", line 193, in _run_module_as_main

[dochtml] "main", mod_spec)

[dochtml] File "/usr/local/lib/python3.7/runpy.py", line 85, in _run_code

[dochtml] exec(code, run_globals)

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/main.py", line 2, in <module>

[dochtml] main()

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/init.py", line 1720, in main

[dochtml] builder()

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/init.py", line 327, in _wrapper

[dochtml] getattr(get_builder(document), 'inventory')(*args, kwds)

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/init.py", line 552, in _wrapper

[dochtml] self._build_everything_except_bibliography(lang, format, *args, kwds)

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/init.py", line 538, in _build_everything_except_bibliography

[dochtml] build_many(build_ref_doc, non_references)

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/init.py", line 280, in build_many

[dochtml] _build_many(target, args, processes=NUM_THREADS)

[dochtml] File "/usr/ports/math/sage/work/stage/usr/local/lib/python3.7/site-packages/sage_setup/docbuild/utils.py", line 283, in build_many

[dochtml] raise worker_exc.original_exception

[dochtml] NameError?: Singular library 'freegb.lib' not found

gmake[4]: * [Makefile:1985: doc-html] Error 1

Note: on my machine freegb.lib is installed under /usr/local/share/singular/LIB/freegb.lib

[mkoeppe]

dup of #29024

[gh-thierry-FreeBSD]

OK, to be closed!

(Because #29024 is not listed in #27330 I did not found it)