[WIP] Download IDAKLU from pybammsolvers

[kratman]

Description

This will separate the IDAKLU C++ code from pybamm.

Type of change

This should speed up CI by skipping the build of the C++ code.

• Optimization (back-end change that speeds up the code)

Key checklist:

• No style issues: $ pre-commit run (or $ nox -s pre-commit) (see CONTRIBUTING.md for how to set this up to run automatically when committing locally, in just two lines of code)
• All tests pass: $ python run-tests.py --all (or $ nox -s tests)
• The documentation builds: $ python run-tests.py --doctest (or $ nox -s doctests)

You can run integration tests, unit tests, and doctests together at once, using $ python run-tests.py --quick (or $ nox -s quick).

Further checks:

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[kratman]

A new link error cropped up, but it looks like we could get a lot of savings on time with this update.

Edit: Most of the run time appears to be in the integration tests, so unfortunately the time savings are not as good as I would have hoped.

[agriyakhetarpal]

The linkage error is the same one as #3783, coming from CasADi's plugin system. I am not sure if it's worth fixing it, since it was fixed by @martinjrobins for the linear interpolant case by dropping down to Python but IIRC there wasn't a way in CasADi for doing it for the cubic

[kratman]

@agriyakhetarpal Yeah I was looking at that issue as well. As far as I can tell CasADI sets a path for plugins. I am trying to see if there is a decent workaround since this was part of #4464

My guess is that the wheels for the next release will be broken as well, but I have not confirmed it yet

[agriyakhetarpal]

There is a workaround for Linux and macOS, but not for Windows (different toolchain); sadly, it's not decent enough to include. I think I'll raise a PR upstream in CasADi to get one part of the linkage going and see if we can migrate to a non-MSVC toolchain (which can potentially help provide that workaround for this on Windows later on). It's been on my list of things to do for a while, but I've yet to do it.

[kratman]

This is fixed locally with this: export CASADIPATH=.venv/lib/python3.12/site-packages/casadi

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 1 line in your changes missing coverage. Please review.

Project coverage is 98.82%. Comparing base (444ecc1) to head (77219ae).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
src/pybamm/__init__.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4487      +/-   ##
===========================================
- Coverage    99.41%   98.82%   -0.60%     
===========================================
  Files          293      293              
  Lines        22554    22548       -6     
===========================================
- Hits         22423    22282     -141     
- Misses         131      266     +135     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[agriyakhetarpal]

This is fixed locally with this: export CASADIPATH=.venv/lib/python3.12/site-packages/casadi

Yes, won't work with Windows