UnknownExistentialVariable compiler bug triggered by delaying a higher-rank function

[pchiusano]

Self-contained example:

f : (forall a . a -> a) -> Nat
f id = id 0

x = 'f

Results in:

UnknownExistentialVariable:
  unsolved

Seems like any higher rank function will do it. (Like try x = ‘Scope.run)

Not sure the urgency on this but it does make it impossible to link to higher rank functions in the docs. I’m hoping it’s just something easy to fix.