In src/mman/mmap.c mmap (after light einval checks) just returns the result
of the syscall directly. But presumably the OS returns -E* and not -1 for
all failures. Otherwise something like EBADF could never go reported.
Presumably musl is compliant here and returns -1 on error and not the
negative value from the OS but I’m not seeing that logic. Am I missing
something here? Thanks.

Best,
Alex