T8987.hs:1:1: error: Exception when trying to run compile-time code: Prelude.undefined CallStack (from HasCallStack): error, called at libraries/base/GHC/Err.hs:79:14 in base:GHC.Err undefined, called at T8987.hs:6:23 in main:T8987 Code: reportWarning ['1', undefined] >> return []