Tests no longer work in Windows

[Dimosts]

Tests do not work in windows machines any more. That is due to trying to import exact, which leads to an error.

Also, exact does not work in windows for the same reason.

[tias]

exact's supported() properly has a try/except, so that should be fine. Also all tests have a 'skipif' guard as they should

Which test is failing?

[Dimosts]

If I remove all exact references from tests, + remove exact from base solvers, tests complete normally. So, it is a problem with exact.

Inspecting it a bit more, it seems that it fails everytime it tries to import exact, throwing the following errors:

• Windows fatal exception: access violation
• fatal error: 'new' file not found
• fatal error: 'vcruntime.h' file not found

[Wout4]

It is indeed exact that does not work on windows

[Dimosts]

I have examined it a bit more.

So, exact imports cppyy. It needs cppyy version 2.4.1 and does not work with the newst version which is 3.0.0.

cppyy version 2.4.1 needs clang9. Newer versions of MSVC in windows stopped supporting clang9. Having this, it yields a windows fatal error which cannot be handled as an import error.

Thus, everoyne that has updated MSVC the last 2 years, will have this error.

Personally I solved it by going my MSVC back to a version of 2019, and now I can run tests. However, I still cannot use exact in windows, as there is now a conflict with another library (boost, c++ linrary this time), which however causes import error in exact, being hangled by try/except.