exago+python fails to build with Spack on Ascent

[nkoukpaizan]

I'm in the process of upgrading the Ascent build system to use a Spack submodule (see diff), and I am getting build errors for ExaGO:

Error sample

>> 327    CMakeFiles/test_pflow_functionality.dir/selfcheck.cpp.o: In function 'fmt_row(std::ostream&, int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':

>> 328    selfcheck.cpp:(.text+0x824): undefined reference to 'std::__cxx11::basic_stringstream<char, std::char_traits<char>, std::allocator<char> >::basic_stringstream()'

I narrowed it down to +python variant, as the build works for ~python, though it could be something else that happens to be triggered with +python. The old modules still work on Ascent with the develop branch (Python included), and the Spack build seems to work on Summit. I am not sure what could be causing the current issue on Ascent.

CC: @cameronrutherford

[cameronrutherford]

Can you make a draft PR with these changes so that I can test this out and help debug? The diff is great but I think that would serve code review a little better.

I imagine this is some compiler error that we are having that hasn't come up on any other platforms before. Other ideas are to do with logging enabled/disabled affecting our python wrapper, and perhaps the PETSc/other versions that you are pinning.

It's also unclear from that backtrace what actual line is causing the error. It is also possible that shared/static libs is part of the problem here, but hard to say. I also notice that you are a fan or merge commits as opposed to rebasing, and so just wondering if that woudl affect things.

We also are moving away from using fmt through a TPL and instead favoring a newer C++ standard (cc @jaelynlitz on this since we were 90% of the way there iirc), so hopefully this gets less problematic.