Handling of newly added files in build system
I think my latest commit fixed this, but won't close the bug until I've added a few files in real life (as opposed to contrived test cases) and seen them correctly recognized. I've been fooled before.
This seems like it's stable enough to close now - if trouble happens again, it'll probably be a new bug instead of a recurrence of the old.
The dependency calculation doesn't work well when a new .mp file is created; it often fails to trigger a re-build of makefile-pfb.inc, so that the next few builds fail. Several ad-hoc fix attempts have been applied, but it's tricky to debug them because if makefile-pfb is ever rebuilt, then the immediate symptoms vanish even if the problem is not really fixed. This requires more careful examination to get it really right.