test symlinks on symlink-capable os but non-capable filesystem (issue1149) The "real" way to test this is to mount a non-symlink-capable filesystem, and try working on it; however, I don't know how to mount filesystems as a non-priveleged user from within the testing framework. So instead, os.symlink is overridden to raise the exception that would be raised on such a filesystem.

util: set_flags should survive failure to create link

util: set_flags shouldn't know about repo flag formats