MR submitted; the code path in file_unix.cpp that uses struct timeval is always setting the usec to 0, which seems wrong (well, it uses st_atime, which is the old-old stat field with just seconds, so there's no much you can do there). The whole ifdeffery on OS seems a bit off, I think some smarts around the available fields of struct stat is in order. If st_atim exists and is a struct timespec then it should go to the code path dealing with struct timespec.

.. like, exactly the same thing is going to happen with OpenBSD, since the MR adds only Q_OS_FREEBSD to the list. I'll see if I can come up with some SFINAE trickery.