The code is, indeed, suboptimal, but not incorrect, while your build process is somewhat misconfigured. Third-party code should not be processed with strict error settings, as it makes the build unnecessarily fragile and prone to failure like in your case. You should modify your build recipe to include Nunavut-generated headers as system headers to fix the problem. For GCC and clang, the correct flag is -isystem, which replaces -I.

I'm only partially convinced. If OpenCyphal targets reliable systems its to be expected that whole codebase (including auto-generated code) does not break when using -Werror. This error may be trivial, but others may be not.

The matter of -Werror is orthogonal to the integrity of the codebase. Compilers are known to occasionally produce false diagnostics, which are promoted to build-breaking errors when strict compilation settings are given. This causes the compiler to reject valid code. It is, generally speaking, impossible to produce any non-trivial code that is certain to emit no diagnostics from all existing standard-compliant compilers. It follows that:

1. -Werror and similar strict options should only be used with the code you control directly and never be applied to third-party code.
2. Build error with -Werror does not indicate that the code is invalid or otherwise unacceptable.

I'm inclined to accept this bug. I don't like normalizing deviance and if we can generate code that avoid well-known compiler warnings we should.

This should be fixed with 2.0.7