Did that. Fastest is msvc natively via cmake (3m). Slowest is mingw on windows via autotools (>30m). clangcl vs msvc was not much difference (less than 30s diff

Did that. Fastest is msvc natively via cmake (3m). Slowest is mingw on windows via autotools (>30m). clangcl vs msvc was not much difference (less than 30s diff). linux builds are from 3m (cmake) to 8m (autotools). clangcl on WSL it would be much faster, but msvc natively would beat it, esp. if you turn off the virus scanner and inherited filesystem permissions. The sheer amount of additional msvc warnings (integer promotion should not really warn) would slow it down though.