[Python-Dev] Raise OSError or RuntimeError in the OS module?

Hi, I introduced recently the signal.pthread_sigmask() function (issue #8407). pthread_sigmask() (the C function) returns an error code using errno codes. I choosed to raise a RuntimeError using this error code, but I am not sure that RuntimeError is the best choice. It is more an OS error than a runtime error: should signal.pthread_sigmask() raise an OSError instead? signal.signal() raises a RuntimeError if setting the signal handler failed. signal.siginterrupt() raises also a RuntimeError on error. signal.setitimer() and signal.getitimer() have their own exception class: signal.ItimerError, raised on setimer() and getitimer() error. Victor