-#!/bin/sh -xe
+#!/bin/sh -e
# apt-get install debian-keyring
-gpg --keyserver pgp.mit.edu --recv-keys $1 && gpg --armor --export $1 | apt-key add -
+test -z "$1" && echo "Usage: $0 key-hash" && exit 1
+key=$1
+
+set -x
+
+gpg --keyserver pgp.mit.edu --recv-keys $key && gpg --armor --export $key | apt-key add -