I've noticed recently that tests/hd-geo-test.c creates test disk images which are 4GB in size, which is a problem if the filesystem on the host doesn't support sparse files. In particular, OSX's HFS+ doesn't have sparse file support, and Windows probably doesn't either. Worse, if the test fails an assertion somewhere the test doesn't clean up after itself and leaves a 4GB file lying around in /tmp/.
It would be nice if we could skip these tests on filesystems that don't have sparse file support... thanks -- PMM