Invalid CMake cache in Flutter

AndroidStudio - and flutter build - gave me this error on an FFI project:

"../poc/flutter-native-arrays/example/linux/CMakeLists.txt" does not match the source  ".../poc/flutter-native-arrays/linux/CMakeLists.txt" 

It seems like invalid cache.

• flutter clean did not help
• Invalidate Caches in AndroidStudio did not help

What did help was:

• deleting the build directory from the project