Error found:
in module Main
at tests/purs/failing/CoercibleHigherKindedData.purs:13:17 - 13:23 (line 13, column 17 - line 13, column 23)

  No type class instance was found for
                                        
    Prim.Coerce.Coercible (Unary t5)    
                          (Binary a3 t5)
                                        
  The instance head contains unknown type variables. Consider adding a type annotation.

while solving type class constraint
                                                                 
  Prim.Coerce.Coercible (Proxy @(t0 -> Type) (Unary @t0))        
                        (Proxy @(t1 -> Type) (Binary @t2 @t1 a3))
                                                                 
while checking that type forall (a :: Type) (b :: Type). Coercible @Type a b => a -> b
  is at least as general as type Proxy @(t0 -> Type) (Unary @t0) -> Proxy @(t1 -> Type) (... @t1 a3)
while checking that expression coerce
  has type Proxy @(t0 -> Type) (Unary @t0) -> Proxy @(t1 -> Type) (... @t1 a3)
in value declaration unaryToBinary

where a3 is a rigid type variable
        bound at (line 13, column 17 - line 13, column 23)
      t0 is an unknown type
      t2 is an unknown type
      t1 is an unknown type
      t4 is an unknown type
      t5 is an unknown type

See https://github.com/purescript/documentation/blob/master/errors/NoInstanceFound.md for more information,
or to contribute content related to this error.