I'm very far out of my depth here, but from a quick read it seems like there is a commonly used flag SA_RESTART that should automatically retry these system cal

I'm very far out of my depth here, but from a quick read it seems like there is a commonly used flag SA_RESTART that should automatically retry these system calls instead of returning the EINTR error. I've no idea whether the behaviour Apple introduced is allowed by the standard, but it seems that it is at least quite common to not explicitly handle this EINTR error because there is an alternative way to just tell the OS to retry instead of returning this error. So I wouldn't be so quick to claim that the downstream apps are coded improperly.