[_flux]

I don't think that should trigger a reasonable interesting condition one has specified, so that should not happen. So I suppose for non-compiler-bugs you need to check (from the output) that the correct thing is being done, in addition to detecting the actual issue.

[0x457]

Well, that's what I said? If you're "reducing" anything other than a compiler bug (what C-Reduce is made for), you most likely have to execute code.

[_flux]

I was not disagreeing with that, merely pointing out that the reproduction test shouldn't be passing with the minimal runnable C program, or indeed for many many previous iterations before that. In my mind also runnable programs would be tested with grep, instead of relying on the return code of the program.