SpecConstr explodes when compiling module BSP of frag-1.1.2

GHC will get stuck when trying to compile Frag. Steps to reproduce:

1. Get Frag 1.1.2 from the Darcs repository (darcs get http://code.haskell.org/frag), or from snowmantw's !GitHub fork (git clone https://github.com/snowmantw/Frag.git).
2. Fix the code so it'll actually compile:

` diff --git a/src/Textures.hs b/src/Textures.hs index 7383fd8..b5516a5 100644 --- a/src/Textures.hs +++ b/src/Textures.hs @@ -10,6 +10,7 @@ import Graphics.UI.GLUT import TGA (readTga) import Data.Word (Word8) import Foreign.Marshal.Alloc (free) +import Control.Exception (catch, SomeException)

-- read a list of images and returns a list of textures @@ -32,7 +33,8 @@ getAndCreateTexture fileName = do

-- read the image data readImageC :: String -> IO (Maybe (Size, PixelData Word8)) -readImageC path = catch (readTga path) (_ -> do print ("missing texture: "++path) +readImageC path = catch (readTga path) (\e -> do print (e :: SomeException)

•                                             print ("missing texture: "++path)
                                              return Nothing)

  `

1. cabal configure
2. cabal build

GHC will get stuck on the module BSP and consume memory until it crashes. According to this ticket on the GitHub fork mentioned earlier, this problem only occurs with -O2.

When I split the reading part of the module (readBSP and all functions it depends on), it crashed on that part. Will investigate further.

Trac metadata

Trac field	Value
Version	7.6.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
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