Correct the return type of the ..._GET_TZINFO() macros (which return a borrowed reference) and add corresponding properties so people don't have to use them.

https://foss.heptapod.net/pypy/pypy/-/issues/3404

Let a tracing test run slower to prevent div-by-zero crashes in line_profiler due to measured zero runtime.

Reconfigure ccache and add the backend (C/C++) to the cache key to distinguish between the compiler jobs.

Make sure that test failures are easy to find in the logs by putting all information into the assertion.

Difficult to say which is best, but something around 7-9 apparently.
Accumulated C/C++ compile times only ever go up with increasing shard count (tried 5, 7, 8, 9, 12) but the total test time is lowest at 7-9, depending on the specific run. So, let's waste less cycles overall.

Disable "pycontextvar" test in PyPy which (as of 7.3.4) seems to lack the C-API support for context variables.

Also fixes the control flow analysis for loop variable assignments in this case.
Closes https://github.com/cython/cython/issues/3787

Make a test cleaner for what it should test. We do not care whether (Py2) 'str' works as long as unicode strings work.

Resolve a C compiler warning in the fallback code for PyContextVar_Get() due to an invalid conditional expression that was mixing a void command with a pointer value.

Add sort of a "Related Work" section to the github readme that references and compares other Python compiler projects.

Do not install Pythran in 0.29.x on travis since it is currently incompatible and unknown when it will work again.

Closes https://github.com/cython/cython/issues/4061

A bug in distutils means that it tries to export a slightly incorrectly named PyInitU function. The fix in https://bugs.python.org/issue39432 wasn't quite right (`"_name".encode("punycode") != "name".encode("punycode")`) and thus the "unicode_imports" test is failing on Windows 3.8+ when distutils explicitly tries to export a non-existing symbol.

We now create a dummy function with that alternative name so that the export doesn't fail.