Bug#275674: please use traps to ensure removal of builddir

[Yann Dirson]

Maybe an intermediate measure could still be taken, by unmounting bindmounts
from the builddir.  Currently, data loss can happen when one blindly
runs "sudo rm -rf" on such a builddir without first manually checking and unmounting
those.

The gravity of such a mistake depends on root perms on those bindmounted dirs, obviously,
so it may happen that you only have nfs-mounted trees bindmounted, but hey, that's probably
far from the common case (although, but luck, it is mine :)

-- 
Yann Dirson - Bertin Technologies