meson can't find dependency via cmake

[yshui]

Digging through the log files, I found out cmake failed with:

CMake Error at /usr/share/cmake-3.14/Modules/CheckIncludeFile.cmake:93 (try_compile):
 Unknown extension ".c" for file

   [snip]/meson-private/cmake_prometheus-cpp/CMakeFiles/CMakeTmp/CheckIncludeFile.c

 try_compile() works only for enabled languages.  Currently these are:

   C CXX

 See project() command to enable other languages.

Which is a really absurd error.

Going into the mentioned directory then run cmake manually works.

meson version is 0.51.0

[mensinda]

Could you please attach the full log (via pastebin etc.) and the name of the dependency?

[yshui]

This is how you reproduce this problem: https://gist.github.com/yshui/f203c379f501cecf4923000bcecc804c

Note, if you comment out the find_dependency(Threads) line in the .cmake, this problem goes away.

@mensinda

[colatkinson]

I can confirm that this is also affecting me with meson 0.51.0 on Windows 10. I can provide logs if it would be helpful.

[mensinda]

Should be fixed with #5630.

[yshui]

Thanks!