Error found:
in module Main
at tests/purs/failing/ClassHeadNoVTA3.purs:8:16 - 8:36 (line 8, column 16 - line 8, column 36)

  No type class instance was found for
                         
    Main.MultiMissing Int
                      t2 
                         
  The instance head contains unknown type variables.

  Note: The following type class members found in the expression require visible type applications to be unambiguous (e.g. tyClassMember @Int).
    Main.useMultiMissing
      tyNotAppearInBody, norThisOne

while checking that type forall (@norThisOne :: t0). MultiMissing @t1 @t0 Int norThisOne => Int
  is at least as general as type Int
while checking that expression useMultiMissing
  has type Int
in value declaration multiMissing

where t1 is an unknown type
      t0 is an unknown type
      t2 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.