> the developer responds by saying they have manually checked the generated assembler to make sure the assembler is correct at the ISA level even though the C code is wrong at the abstract C machine level, and they commit to checking this in the future.

Yeah, sounds about right about quite a lot of the C programmers except for the "they commit to checking this in the future" part. I've responses like "well, don't upgrade your compiler; I'm gonna put 'Clang >= 9.0 is unsupported' in the README as a fix".