Make swig mandatory and therefore NSGA2 a default optimizer

[ewu63]

Purpose

SWIG used to be an optional dependency, but nowadays it is hosted on pyPI and relatively easy to include. Therefore, I propose that we make SWIG a required build dep and therefore NSGA2 an optimizer that is built by default. This will also hopefully simplify some issues people have regarding installation.

Expected time until merged

A few days, preferably after #434.

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Checklist

• I have run flake8 and black to make sure the Python code adheres to PEP-8 and is consistently formatted
• I have formatted the Fortran code with fprettify or C/C++ code with clang-format as applicable
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.97%. Comparing base (3b50b66) to head (353aa81).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #435   +/-   ##
=======================================
  Coverage   85.97%   85.97%           
=======================================
  Files          22       22           
  Lines        3315     3315           
=======================================
  Hits         2850     2850           
  Misses        465      465           

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[marcomangano]

I think this makes a lot of sense!
FYI, the tests are passing, but then the Azure runner encounters a segfault at the very end:

.github/test_real.sh: line 14:  1804 Segmentation fault      (core dumped) testflo --pre_announce --disallow_deprecations -v --coverage --coverpkg pyoptsparse $EXTRA_FLAGS

[eirikurj]

This is probably the same issue that I reported in #340. I did look into this a bit and have a branch here with a few fixes. I need to take a look at this again, but I think there might be still some work to do there. Feel free to debug this and add to this branch.

[ewu63]

Waiting for #438 to be merged first.

[marcomangano]

@eirikurj do you have comments or can we merge this?

[eirikurj]

looks good