function cabal() (
  if [ "$1" = "install" ]; then
    out=$(command cabal --dry-run -v2 "$@" 2>&1)
    if echo "$out" | egrep -c '\((reinstall|new version)\)' >/dev/null; then
      echo "$out"
      echo "
[NOTE] To proceed with installation, possibly breaking packages above, run
[NOTE]     > command cabal $*"
      return 1
    fi
  fi
  command cabal "$@"
)