10 bucks says the lesson learned will be "remember kids, always set -u (and other good ideas, like set -e, set -o pipefail, and personally I like set -o posix b

10 bucks says the lesson learned will be "remember kids, always set -u (and other good ideas, like set -e, set -o pipefail, and personally I like set -o posix but you'll need to give up process substitution for that)."