I am configuring CMake to use Ninja with MSVC 2019 on a CI machine. I am running vcvars64.bat before hand, but for some reason the PATH is not being updated, so I’ve manually added the proper entires to find cl.exe, rc, and mt successfully.

However now that it is configuring successfully and compiling, it is immediately failing not finding any system include directories.

FAILED: BodyData.cpp.obj 
C:PROGRA~2MICROS~32019COMMUN~1VCToolsMSVC1429~1.301binHostx64x64cl.exe  /nologo /TP 
-external:W0 /DWIN32 /D_WINDOWS /W3 /GR /EHsc /Zi /Ob0 /Od /RTC1 -std:c++17 -MDd /wd4244 /bigobj /showIncludes
/FS -c BodyData.cpp
BodyData.h(3): fatal error C1083: Cannot open include file: 'cstdint': No such file or directory

I see the INCLUDE environment variable is populated with all the correct paths, so I wonder what I am missing for Ninja to use it? It works perfectly on my local machine of course.