The tar files we're making of artifacts don't include parent
directories. Now we could change the builder to make them, but we can
also just autocreate them on import. Mode 0755 with no xattrs seems
OK here.
It's pretty trivial to map a previously existing commit tree into a
mutable tree too. While we're here change the command line arguments
for commit so that we can now properly overlay any combination of
directory, commit, or tarfile.
ostbuild will generate two artifacts: foo-runtime.tar.gz and
foo-devel.tar.gz in the general case. When committing to the devel
tree, it'd be lame (i.e. slower and not atomic) to have to commit
twice.
We really want the ability to take a .tar.gz and directly import
it into a repository, without creating a temporary filesystem tree.
First, doing it this way is significantly faster. Also, this allows
us to handle importing tar files with e.g. uid 0 files into packed
repositories as non-root, which is very useful for tests and builds.
Colin Walters