Revert "Improve just a little"

This reverts commit dd9017fac6532cbb3d6283d6046b7c9a06be9d83.
Revert "Make -f faster"

This reverts commit 7a89a02541755274338e34f3b6abeb762440d4ba.

That commit makes it impossible to extract failed modules while
tinderbox is running.