I'd be happier with some documentation, again.
If I've understood this test correctly (which I'm very unsure about), the documentation I'd add would be
```
OK if we fail to expand at all (promising '$(watch)' unexpanded) or expand (so succeed, as "/" exists), but not if the parser treated '@(given_watch)' as a literal string entry in the slist, so expanded to that string.
```
If I haven't understood this test correctly, you have proof that it needs documentation !