Clang on windows

I am trying to use clang in windows. There seems to be some issue with the LD_LIBRARY_PATH environment variable but I’m not sure what it should be set to

Relevant build
https://travis-ci.org/saulius/croaring-rs/builds/478338198

Error

cargo:warning=CRoaring/roaring.h:39:10: fatal error: 'stdlib.h' file not found

Any help is greatly appreciated

Thanks in advance