HS_DIR=/usr/share/haskell/haskell-x11-xft
post_install() {
  ${HS_DIR}/register.sh 2> /dev/null
}
pre_upgrade() {
  ${HS_DIR}/unregister.sh 2> /dev/null
  exit 0
}
post_upgrade() {
  ${HS_DIR}/register.sh 2> /dev/null
}
pre_remove() {
  ${HS_DIR}/unregister.sh 2> /dev/null
}