Resolving dependencies... Configuring mtl-2.2.1... Configuring old-locale-1.0.0.7... Building mtl-2.2.1... Building old-locale-1.0.0.7... Installed old-locale-1.0.0.7 Configuring pcre-light-0.4.0.4... Building pcre-light-0.4.0.4... Configuring readline-1.0.3.0... Installed mtl-2.2.1 Configuring old-time-1.1.0.3... Installed pcre-light-0.4.0.4 Building readline-1.0.3.0... Building old-time-1.1.0.3... Installed readline-1.0.3.0 Installed old-time-1.1.0.3 Configuring mkcabal-0.4.1.1... Building mkcabal-0.4.1.1... Failed to install mkcabal-0.4.1.1 Build log ( /home/builder/.cabal/logs/mkcabal-0.4.1.1.log ): cabal: Entering directory '/tmp/cabal-tmp-23211/mkcabal-0.4.1.1' Configuring mkcabal-0.4.1.1... Building mkcabal-0.4.1.1... Preprocessing executable 'mkcabal' for mkcabal-0.4.1.1... mkcabal.hs:1:16: warning: -fglasgow-exts is deprecated: Use individual extensions instead [1 of 2] Compiling Licenses ( Licenses.hs, dist/build/mkcabal/mkcabal-tmp/Licenses.o ) [2 of 2] Compiling Main ( mkcabal.hs, dist/build/mkcabal/mkcabal-tmp/Main.o ) mkcabal.hs:384:14: error: • Ambiguous type variable ‘e0’ arising from a use of ‘handle’ prevents the constraint ‘(Exception e0)’ from being solved. Probable fix: use a type annotation to specify what ‘e0’ should be. These potential instances exist: instance Exception NestedAtomically -- Defined in ‘Control.Exception.Base’ instance Exception NoMethodError -- Defined in ‘Control.Exception.Base’ instance Exception NonTermination -- Defined in ‘Control.Exception.Base’ ...plus 17 others ...plus two instances involving out-of-scope types (use -fprint-potential-instances to see them all) • In the expression: handle (\ _ -> return $ pair defNameAndMail) In the expression: handle (\ _ -> return $ pair defNameAndMail) $ do { env <- getEnvironment; let p | Just e <- lookup "DARCS_EMAIL" env = break (== '<') e | Just e <- lookup "EMAIL" env = ... | otherwise = pair defNameAndMail; return p } In a stmt of a 'do' block: if he then readFile authorHome >>= return . nameAndMail else handle (\ _ -> return $ pair defNameAndMail) $ do { env <- getEnvironment; let p | Just e <- lookup "DARCS_EMAIL" env = ... | Just e <- lookup "EMAIL" env = ... | otherwise = ...; return p } cabal: Leaving directory '/tmp/cabal-tmp-23211/mkcabal-0.4.1.1' cabal: Error: some packages failed to install: mkcabal-0.4.1.1 failed during the building phase. The exception was: ExitFailure 1