pre_upgrade() { echo '==> Unregistering cabalized packages...' [[ -d /usr/share/haskell ]] && find /usr/share/haskell -maxdepth 2 -name 'unregister.sh' -exec {} \; echo '==> Done.' } post_upgrade() { echo '==> All cabalized packages need to be reinstalled now.' echo '==> See /usr/share/haskell/ for a tentative list of affected packages.' }