when it try to do this

             lprog <- G.labelNew Nothing

The error says:

Could not deduce (glib-0.13.4.1:System.Glib.UTFString.GlibString string0) arising from a use of ‘G.labelNew’ from the context (D.Rel c v a s) bound by the type signature for sourceWindowCreate :: D.Rel c v a s => RSourceView c a u -> IO G.Widget at Debug/SourceView.hs:913:23-73 instance glib-0.13.4.1:System.Glib.UTFString.GlibString [Char] -- Defined in ‘glib-0.13.4.1:System.Glib.UTFString’ In a stmt of a 'do' block: lprog <- G.labelNew Nothing In the expression: do { vbox <- G.vBoxNew False 0; G.widgetShow vbox; spec <- getIORef svInputSpec ref; code <- codeWinNew spec; .... } In an equation for ‘sourceWindowCreate’: sourceWindowCreate ref = do { vbox <- G.vBoxNew False 0; G.widgetShow vbox; spec <- getIORef svInputSpec ref; cabal: Error: some packages failed to install:

I really don't know how to proceed, I'm new with Haskell 

Thanks in advance.