#9514: Haddock panics when exporting a module with pattern synonyms -------------------------------------+------------------------------------- Reporter: Artyom.Kazak | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.3 Keywords: haddock | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: Compile- Difficulty: Unknown | time crash Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- First of all: Haddock version: '''2.14.3''', GHC version: '''7.8.3'''. Create 2 files, `PatSymDef.hs` and `PatSymUse.hs`: {{{#!hs -- PatSymDef.hs {-# Language PatternSynonyms #-} module PatSymDef where pattern Pat = () }}} {{{#!hs -- PatSymUse.hs {-# Language PatternSynonyms #-} module PatSymUse (module PatSymDef) where import PatSymDef }}} Run Haddock on them: {{{ [yom@shiny tmp]$ haddock -h PatSymDef.hs PatSymUse.hs Haddock coverage: Warning: Not found in environment: PatSymDef.Pat 50% ( 1 / 2) in 'PatSymDef' haddock: panic! (the 'impossible' happened) (GHC version 7.8.3 for x86_64-unknown-linux): mkUsage <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} And with `-ddump-if-trace`: {{{ [yom@shiny tmp]$ haddock -h PatSymDef.hs PatSymUse.hs --optghc='-ddump-if- trace' Haddock coverage: Considering whether to load base:Prelude Reading interface for base:Prelude; reason: Prelude is directly imported readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Prelude.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Prelude.dyn_hi updating EPS_ updating EPS_ Considering whether to load base:GHC.Base {- SYSTEM -} Reading interface for base:GHC.Base; reason: Loading orphan modules (base:GHC.Base) readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Base.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Base.dyn_hi updating EPS_ Considering whether to load base:GHC.Float {- SYSTEM -} Reading interface for base:GHC.Float; reason: Loading orphan modules (base:GHC.Float) readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Float.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Float.dyn_hi updating EPS_ Considering whether to load base:GHC.Real {- SYSTEM -} Reading interface for base:GHC.Real; reason: Loading orphan modules (base:GHC.Real) readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Real.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/GHC/Real.dyn_hi updating EPS_ loadHiBootInterface main:PatSymDef Starting fork { Declaration for Monad Loading decl for GHC.Base.Monad updating EPS_ Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} Reading interface for ghc-prim:GHC.Prim; reason: Need home interface for wired-in thing * updating EPS_ Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} tc-iface-class1 Monad tc-iface-class2 Monad tc-iface-class3 Monad tc-iface-class4 Monad buildClass buildClass GHC.Base.Monad } ending fork Declaration for Monad Need decl for Control.Applicative.Applicative Considering whether to load base:Control.Applicative {- SYSTEM -} Reading interface for base:Control.Applicative; reason: Need decl for Control.Applicative.Applicative readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Control/Applicative.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Control/Applicative.dyn_hi updating EPS_ Starting fork { Declaration for Applicative Loading decl for Control.Applicative.Applicative updating EPS_ Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} tc-iface-class1 Applicative tc-iface-class2 Applicative tc-iface-class3 Applicative tc-iface-class4 Applicative buildClass buildClass Control.Applicative.Applicative } ending fork Declaration for Applicative Need decl for Control.Monad.MonadPlus Considering whether to load base:Control.Monad {- SYSTEM -} Reading interface for base:Control.Monad; reason: Need decl for Control.Monad.MonadPlus readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Control/Monad.hi readIFace /usr/lib/ghc-7.8.3/base-4.7.0.1/Control/Monad.dyn_hi updating EPS_ Starting fork { Declaration for MonadPlus Loading decl for Control.Monad.MonadPlus updating EPS_ Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} tc-iface-class1 MonadPlus tc-iface-class2 MonadPlus tc-iface-class3 MonadPlus tc-iface-class4 MonadPlus buildClass buildClass Control.Monad.MonadPlus } ending fork Declaration for MonadPlus Starting fork { Declaration for Alternative Loading decl for Control.Applicative.Alternative updating EPS_ Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} Considering whether to load ghc-prim:GHC.Prim {- SYSTEM -} tc-iface-class1 Alternative tc-iface-class2 Alternative tc-iface-class3 Alternative tc-iface-class4 Alternative buildClass buildClass Control.Applicative.Alternative } ending fork Declaration for Alternative ==================== Interface statistics ==================== Renamer stats: 7 interfaces read 4 type/class/variable imported, out of 1234 read 0 instance decls imported, out of 97 read 0 rule decls imported, out of 53 read Need decl for PatSymDef.Pat Considering whether to load main:PatSymDef {- SYSTEM -} Warning: Not found in environment: PatSymDef.Pat 50% ( 1 / 2) in 'PatSymDef' Considering whether to load base:Prelude Considering whether to load main:PatSymDef updating EPS_ Considering whether to load base:GHC.Base {- SYSTEM -} Considering whether to load base:GHC.Float {- SYSTEM -} Considering whether to load base:GHC.Real {- SYSTEM -} loadHiBootInterface main:PatSymUse haddock: panic! (the 'impossible' happened) (GHC version 7.8.3 for x86_64-unknown-linux): mkUsage <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9514 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler