Hi, Raef,

I can get past the CMSIS issue by dup'ing the GNU links. It now fails for lack of the correct Python.

Using the -G option, CMakeCache.txt lists all the pythons in my system and the build completes: $ grep python cmake_build/CMakeCache.txt PYTHON_EXECUTABLE:FILEPATH=C:/Python/Python27/python.exe FIND_PACKAGE_MESSAGE_DETAILS_Python3:INTERNAL=[C:/Users/cXXXXX/AppData/Local/Programs/Python/Python38-32/python.exe][cfound components: Interpreter ][v3.8.5()] _Python3_EXECUTABLE:INTERNAL=C:/Users/cXXXXX/AppData/Local/Programs/Python/Python38-32/python.exe

Without the -G option, the compiler is MSVC, and the cache has no entry for python at all. Building Custom Rule C:/Users/cXXXXX/Git/arm/TF-M/trusted-firmware-m/cmake_build/lib/ext/mcuboot-subbuild/CMakeLists.txt Building Custom Rule C:/Users/cXXXXX/Git/arm/TF-M/trusted-firmware-m/cmake_build/lib/ext/mcuboot-subbuild/CMakeLists.txt -- Could NOT find Python3 (missing: Python3_EXECUTABLE Interpreter) Reason given by package: Interpreter: Wrong major version for the interpreter "C:/Python/Python27/python.exe"