Internal error in Mimer with module parameter and matching

[Andreas Abel]

module _ (A : Set) where

open import Agda.Builtin.Nat
open import Agda.Builtin.Sigma

data Color : Set where
  black : Color

data Tree' : Color → Nat → Set where
  nb : ∀ (a : A) {c} {n}
     → Tree' c n
     → Tree' black n
     → Tree' black (suc n)

test : ∀ (a : A) {n} (l : Tree' black (suc n)) → Σ _ λ c → Tree' c (suc n)
test a (nb a₁ l l₁) = {!!} --internal error C-c C-a

-- An internal error has occurred. Please report this as a bug.
-- Location of the error: __IMPOSSIBLE__, called at src/full/Agda/TypeChecking/CompiledClause/Match.hs:87:73

Looks like this impossible is hit (last line):

agda/src/full/Agda/TypeChecking/CompiledClause/Match.hs

Lines 75 to 87 in c0ceac7

 -- done matching 
 Done xs t 
   -- if the function was partially applied, return a lambda 
   | m < n     -> yes $ applySubst (toSubst es) $ foldr lam t (drop m xs) 
   -- otherwise, just apply instantiation to body 
   -- apply the result to any extra arguments 
   | otherwise -> yes $ applySubst (toSubst es0) t `applyE` map ignoreReduced es1 
   where 
     n              = length xs 
     m              = length es 
     -- at least the first @n@ elims must be @Apply@s, so we can 
     -- turn them into a subsitution 
     toSubst        = parallelS . reverse . map (unArg . fromMaybe __IMPOSSIBLE__ . isApplyElim . ignoreReduced)