Stage MG5 and NI6 are contradictory. MG5 uses common shell command names to search in provided path and expects a different response than a shell built-in. However, in NI6 one of these commands (cat) ends up becoming a shell built-in. Ideally, ‘is a shell built in’ should be the expected type command response for cat, but the earlier MG5 tests expect it to be different (cat is /path/to/cat).
This should be fixed IMO.