OpenBSD's ports tree gets compiled using multiple compilers (clang/gcc) and compiler versions (base 4.2.1, ports gcc8/11), across many different architectures.

OpenBSD's ports tree gets compiled using multiple compilers (clang/gcc) and compiler versions (base 4.2.1, ports gcc8/11), across many different architectures. In most cases when an upstream has added -Werror to a Makefile, they have not considered this. It's good for testing, but not for reliably compiling software.