@@ -71,7 +71,7 @@ fetchOrFromDB optHpack hackageDB src
7171 | otherwise = do
7272 r <- fetch (\dir -> cabalFromPath optHpack (dir </> sourceCabalDir src)) src
7373 case r of
74− Nothing -> fail "Failed to fetch source. Does the URL exist?"
74+ Nothing -> fail $ "Failed to fetch source. Does this source exist? " ++ show src
7575 Just (derivSource, (externalSource, ranHpack, pkgDesc)) ->
7676 return (derivSource <$ guard externalSource, ranHpack, pkgDesc)
7777