It's still the case that we have to guess that a generic EINVAL (22) is actually EPIPE. Low-level wrapper functions in Python/fileutils.c, such as _Py_read() and _Py_write_impl(), should try to get a better error code by calling Python's custom winerror_to_errno() mapping function on the CRT's _doserrno value. For example:

_Py_read:

    #ifdef MS_WINDOWS
            n = read(fd, buf, (int)count);
            if (n < 0 && errno == EINVAL) {
                errno = winerror_to_errno(_doserrno);
            }

_Py_write_impl:

    #ifdef MS_WINDOWS
                n = write(fd, buf, (int)count);
                if (n < 0 && errno == EINVAL) {
                    errno = winerror_to_errno(_doserrno);
                }

This maps ERROR_NO_DATA to EPIPE.