< Migrating from Arch to GUIX, or, An Exercise in Toe-Dipping
I imagine it would be very possible, but I'm not sure just how much of a space gain you would get from it -- builds often aren't entirely reproducible and even when they are, different distros may package them with slightly different build-time configuration.
The overhead of adding a new codepath (and possibly replacing a new part of the filesystem with more FUSE) would, I suspect, heavily outweigh the benefits, although I've been wrong before.
Ah true -- I forgot how those pesky timestamps ruin everything. I still don't understand why they're needed in builds.