cooldome

Looks like CI is using gcc 5.5 which doesn't support required C++ feature. The best option is to upgrade the CI

If I got it correctly mingw is taken from nim website https://nim-lang.org/download/mingw64.7z. Who has permission to upgrade it?

The first gcc version that has the necessary feature is 8.0. https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/8.1.0/threads-win32/seh/x86_64-8.1.0-release-win32-seh-rt_v6-rev0.7z/download should work. Let me test it later today.

I have tried gcc 8.1 I have proposed above and I haven't experienced any issues, checked for issues mentioned in #9375 as well. I think it is ok to upgrade.

If there si objection to gcc 8.1 there is tdm-gcc 9.2 https://jmeubank.github.io/tdm-gcc/articles/2020-03/9.2.0-release. I also had good experience with it but it comes with installer.

tested, #17017 is not a problem on mingw 8.1

I have reviewed this PR and really like it. Only two comment I have: - I don't think you need to introduce `wInternalProc` pragma, you can use `compilerProc` pragma and...

I have checked again and i think it safe to assume that wrapped proc can always raise exception, little overhead is added for potential exception handling.

a,b,c are not defined in the test

Compiler crash stacktrace ``` Error: internal error: invalid kind for last(tyAnything) Traceback (most recent call last) nim.nim(121) nim nim.nim(77) handleCmdLine main.nim(163) mainCommand main.nim(74) commandCompileToC modules.nim(240) compileProject modules.nim(180) compileModule passes.nim(215) processModule...