Error looks like this:
[error] (nativeClang) java.io.IOException: Cannot run program "which": CreateProcess error=2, The system cannot find the file specified [error] (nativeClangPP) java.io.IOException: Cannot run program "which": CreateProcess error=2, The system cannot find the file specified
Are you on Windows?
scala-native is supported on POSIX like operating systems (like Linux, macOS, FreeBSD).
Please, see the list of supported OS, at the end of this page:
https://scala-native.readthedocs.io/en/v0.3.9-docs/user/setup.html