Fix elfutils +debuginfod installation issue

[tmadlener]

Fixes #36710

• Add new versions for libmicrohttpd. Also add an older one to make elfutils configure with +debuginfod
• Require libarchive~iconv in order to avoid another configure error.
• Make elfutils depend on pkgconfig explicitly to avoid picking up the system one.

[tmadlener]

#36710 (comment):

I can confirm that the problem initially presented itself with libarchive@3.6.2. Using the previous version allows elfutils to build.

maybe we should make this version dependent then?

[G-Ragghianti]

Sure.

[tmadlener]

Made libarchive@3.6.2 +iconv a conflict. Building against libarchive@3.5.2+iconv works for me as well, and the concretizer is smart enough to figure out libarchive@3.6.2 ~iconv by default.

[G-Ragghianti]

This resolves my issues in building gdb.

[tmadlener]

@hainest would you be OK with this temporary fix until uptream libarchive is fixed?

[hainest]

@tmadlener This works for me. Thanks for working on it!

[mwkrentel]

This is, at best a temporary solution until libarchive sorts itself out, right?

There was an active discussion of this in the libarchive pull requests
in Dec/Jan. The problem centers around iconv being provided by glibc
and how to handle that case (where no extra lib is used) vs a separate
libiconv.

libarchive/libarchive#1825
libarchive/libarchive#1817
libarchive/libarchive#1813
libarchive/libarchive#1812

All of the above are short but a bit different for how they solve the
problem. People argued forcefully for and against different patches.

The last one, 1825 got merged after 3.6.2 was released, although some
people argued that it was the wrong solution.

Anyone know enough about pkgconfig to say what is the "right" solution
here (I don't). As I said, 1825 is now in the libarchive code base,
so maybe go with that?

[tmadlener]

Yes, I would also consider this a temporary solution. I am also no expert in any way in pkgconfig, so I can't weigh in either on which would be the proper way to fix this.

I have however entirely missed that they merged a PR to "fix" this (for a definition of fix). We could also try to apply that patch to libarchive@3.6.2 via spack and see if that let's us remove the conflict here.

[mwkrentel]

@tmadlener @G-Ragghianti @scheibelp
I've been experimenting with possible fixes, including 1825 from
libarchive and I'm going around in circles and getting flustrated.
I believe there is a better fix, but probably not one I'll come
up with in a reasonable time.

So, with the understanding that this is a temporary workaround until
we get the "right fix," I suggest we should merge this and move on.

@scheibelp Why is CI failing? The patch includes:

conflicts("libarchive@3.6.2 +iconv", when="+debuginfod")

And the error message is:

Run . share/spack/setup-env.sh
PKG-DIRECTIVES: 1 issue found
1. elfutils: wrong variant in "conflicts" directive
    the variant 'iconv' does not exist
    in /home/runner/work/spack/spack/var/spack/repos/builtin/packages/elfutils/package.py
Error: Process completed with exit code 1.

Is spack assigning +iconv to elfutils instead of libarchive?
Do I need to write this as ^libarchive +iconv instead of libarchive +iconv
to force iconv to go with libarchive??

Note: libarchive has a +iconv variant, but elfutils does not.

[G-Ragghianti]

Do I need to write this as ^libarchive +iconv instead of libarchive +iconv

Yes I think you just need this change.

[mwkrentel]

@tmadlener I checked with Massimiliano at the Wed spack meeting. Yes, you need
to add the carat ^ to libarchive, that will fix the CI failure.

conflicts("^libarchive@3.6.2 +iconv", when="+debuginfod")

Without the ^, this is interpreted as libarchive@3.6.2 AND +iconv,
that is, two separate things.

[tmadlener]

Thanks for the hint. Fixed now, and CI seems happier.

[tmadlener]

@mwkrentel @hainest I think this needs approval again, after fixing the merge conflict

[tmadlener]

@scheibelp is there anything still missing for this to get merged?

[scheibelp]

Thanks!