The explanatory comment contained an unescaped loop-variable token, which
the local shell (set -u) tried to expand while building the double-quoted
remote script ('unit: unbound variable'). Reword the comment.
The explanatory comment contained an unescaped loop-variable token, which
the local shell (set -u) tried to expand while building the double-quoted
remote script ('unit: unbound variable'). Reword the comment.