Ignored missing lock file

[nicolassidoux]

FileLock Unix implementation for releasing the lock:

        def _release(self) -> None:
            # Do not remove the lockfile:
            #   https://github.com/tox-dev/py-filelock/issues/31
            #   https://stackoverflow.com/questions/17708885/flock-removing-locked-file-without-race-condition
            fd = cast(int, self._context.lock_file_fd)
            self._context.lock_file_fd = None
            fcntl.flock(fd, fcntl.LOCK_UN)
            os.close(fd)

FileLock Windows implementation for releasing the lock:

        def _release(self) -> None:
            fd = cast(int, self._context.lock_file_fd)
            self._context.lock_file_fd = None
            msvcrt.locking(fd, msvcrt.LK_UNLCK, 1)
            os.close(fd)

            with suppress(OSError):  # Probably another instance of the application hat acquired the file lock.
                Path(self.lock_file).unlink()

TLDR: the Windows version of _release() deletes the lock file, while the Unix version doesn't. So on Windows the additional call of Path(lock_path).unlink() after exiting FileLock context causes an exception because the file is not present anymore.

Good thing is unlink() accepts the argument missing_ok=True. This argument makes unlink(missing_ok=True) not to throw an exception if the file is not found, resolving the problem.

[Zethson]

Great, thank you!