It would be nice if ebuilds could set RESTRICT="sparse-files" to assert that sparse files are supported.
Isn't that backwards???
RESTRICT="sparse-files" means to me that they are NOT supported.
I suppose we could make it PROPERTIES="sparse-files" instead. Patrick, sounds good to you?
I am fine with that, the main thing I want is the ability to have the package manager bomb out rather than happily merge a ~100G sparse file as something that is not sparse.
The tar --sparse option is not currently used to pack binary packages.
Current versions of quickpkg do not support creation of sparse entries, and python's tarfile documentation states that sparse file support is read-only:
Maybe there's some way to make the tarfile API write sparse entries that have been manually created somehow. The tar manual has an informative "Storing Sparse Files" section: