#15007: Don't keep shadowed variables in ghci, both renamer and type checker -------------------------------------+------------------------------------- Reporter: sighingnow | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: GHCi | Version: 8.5 Resolution: | Keywords: TypedHoles Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #11547 #14052 | Differential Rev(s): Phab:D4909 #15202 | Wiki Page: | -------------------------------------+------------------------------------- Comment (by sighingnow): This ticket isn't fixed by Phab:D4909. With a debug-enabled stage2 compiler, for the script in description, we will get a panic: {{{ Prelude> 1 1 (0.02 secs, 65,728 bytes) Prelude> 1 1 (0.00 secs, 64,352 bytes) Prelude> _ ghc-stage2.exe: panic! (the 'impossible' happened) (GHC version 8.7.20180629 for x86_64-unknown-mingw32): ASSERT failed! Cur lvl = 1 Imp lvl = 1 Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler\utils\Outputable.hs:1164:37 in ghc:Outputable pprPanic, called at compiler\utils\Outputable.hs:1223:5 in ghc:Outputable assertPprPanic, called at compiler\\typecheck\\TcSimplify.hs:1548:120 in ghc:TcSimplify CallStack (from -prof): HscMain.ioMsgMaybe (compiler\main\HscMain.hs:(252,1)-(257,128)) HscMain.hscParsedStmt (compiler\main\HscMain.hs:(1548,1)-(1564,36)) HscMain.hscStmtWithLocation (compiler\main\HscMain.hs:(1533,1)-(1541,50)) GHC.withCleanupSession (compiler\main\GHC.hs:(469,1)-(477,27)) GHC.runGhc (compiler\main\GHC.hs:(444,1)-(449,26)) GHC.defaultErrorHandler (compiler\main\GHC.hs:(384,1)-(416,7)) }}} Besides, this ticket is intend to solve the problem described in #11547, the ` GHC internal error` (for script reported by #11547) still occurs after Phab:D4909. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15007#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler