BUG: Sorting on a list we've emptied manually and then index into times out

[kcruijss]

Not sure why this happens, but when we sort on a list we empty manually and then indexed into, it times out.

The weird part is, is that when we simply sort on an empty list (i.e. Σ¯) it works fine; if we sort on this empty list after we've indexed into it (i.e. Σ¯Nè) it works fine as well; if we sort on a list we empty manually (i.e. Σ1L¨) it works fine as well, but if we sort on a list we've emptied manually and then indexed into (i.e. Σ1L¨Nè) it doesn't work.

Try it online to reproduce.
Came across it in this codegolf answer of mine.