#7844: Panic messages raised from GHCi don't include details -----------------------------+---------------------------------------------- Reporter: parcs | Owner: Type: bug | Status: new Priority: normal | Component: GHCi Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- In GHC built the `devel2` way, compiling the following source file through GHC causes a compiler panic: {{{ f :: (Num Int => Num) () => () f = undefined }}} {{{ [1 of 1] Compiling Main ( tmp/xxx.hs, tmp/xxx.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.7.20130416 for x86_64-unknown-linux): ASSERT failed! file compiler/types/Type.lhs line 1623 base:GHC.Num.Num{tc 2b} ghc-prim:GHC.Types.Int{(w) tc 3J} => base:GHC.Num.Num{tc 2b} ghc-prim:GHC.Prim.*{(w) tc 34d} -> ghc-prim:GHC.Prim.Constraint{(w) tc 34s} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} However, if you try to compile the same file through GHCi, you get a panic message but without the important details: {{{ Prelude> :load tmp/xxx.hs [1 of 1] Compiling Main ( tmp/xxx.hs, interpreted ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.7.20130416 for x86_64-unknown-linux): ASSERT failed! <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7844 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler