Resolving dependencies... Configuring ObjectName-1.1.0.1... Configuring colour-2.3.3... Building colour-2.3.3... Building ObjectName-1.1.0.1... Installed ObjectName-1.1.0.1 Configuring data-accessor-0.2.2.7... Building data-accessor-0.2.2.7... Configuring fixed-0.2.1.1... Installed data-accessor-0.2.2.7 Building fixed-0.2.1.1... Configuring half-0.2.2.3... Installed colour-2.3.3 Building half-0.2.2.3... Configuring stm-2.4.4.1... Installed fixed-0.2.1.1 Building stm-2.4.4.1... Configuring gd-3000.7.3... Installed half-0.2.2.3 Building gd-3000.7.3... Configuring utility-ht-0.0.12... Installed stm-2.4.4.1 Building utility-ht-0.0.12... Configuring text-1.2.2.1... Installed gd-3000.7.3 Building text-1.2.2.1... Configuring StateVar-1.1.0.4... Installed utility-ht-0.0.12 Building StateVar-1.1.0.4... Configuring data-accessor-template-0.2.1.13... Installed StateVar-1.1.0.4 Building data-accessor-template-0.2.1.13... Installed data-accessor-template-0.2.1.13 Installed text-1.2.2.1 Configuring OpenGLRaw-3.2.4.0... Building OpenGLRaw-3.2.4.0... Installed OpenGLRaw-3.2.4.0 Configuring GLURaw-2.0.0.3... Building GLURaw-2.0.0.3... Installed GLURaw-2.0.0.3 Configuring OpenGL-3.0.1.0... Building OpenGL-3.0.1.0... Installed OpenGL-3.0.1.0 Configuring GLUT-2.7.0.10... Building GLUT-2.7.0.10... Installed GLUT-2.7.0.10 Downloading hfractal-0.4.2.5... Configuring hfractal-0.4.2.5... Building hfractal-0.4.2.5... Failed to install hfractal-0.4.2.5 Build log ( /home/builder/.cabal/logs/hfractal-0.4.2.5.log ): cabal: Entering directory '/tmp/cabal-tmp-14399/hfractal-0.4.2.5' Configuring hfractal-0.4.2.5... Building hfractal-0.4.2.5... Preprocessing executable 'hfractal' for hfractal-0.4.2.5... [1 of 7] Compiling PointComp ( src/PointComp.hs, dist/build/hfractal/hfractal-tmp/PointComp.o ) src/PointComp.hs:3:1: warning: [-Wtabs] Tab character found here, and in 25 further locations. Please use spaces instead. [2 of 7] Compiling FracState ( src/FracState.hs, dist/build/hfractal/hfractal-tmp/FracState.o ) src/FracState.hs:31:1: warning: [-Wtabs] Tab character found here, and in two further locations. Please use spaces instead. [3 of 7] Compiling FracComp ( src/FracComp.hs, dist/build/hfractal/hfractal-tmp/FracComp.o ) src/FracComp.hs:40:9: error: • Non type-variable argument in the constraint: MArray IOUArray Double m (Use FlexibleContexts to permit this) • When checking the inferred type go :: forall (m :: * -> *). MArray IOUArray Double m => Int -> m () In an equation for ‘copyArr’: copyArr end orig dest = go 0 where go !x | x == end = return () | otherwise = do { t <- readArray orig x; .... } cabal: Leaving directory '/tmp/cabal-tmp-14399/hfractal-0.4.2.5' cabal: Error: some packages failed to install: hfractal-0.4.2.5 failed during the building phase. The exception was: ExitFailure 1