Startup: If repo dir check fails, print both versions of repo tree

src/Vervis/Application.hs

@@ -32,6 +32,7 @@ where
 
 import Control.Concurrent.Chan
 import Control.Concurrent.STM.TVar
+import Control.Exception hiding (Handler)
 import Control.Monad
 import Control.Monad.Logger                 (liftLoc, runLoggingT, logInfo, logError)
 import Control.Monad.Trans.Reader
@@ -229,14 +230,19 @@ makeFoundation appSettings = do
     verifyRepoDir = do
         repos <- lift repoTreeFromDir
         repos' <- repoTreeFromDB
-        unless (repos == repos') $
-            error "Repo dir check failed!"
-        liftIO $
-            for_ repos $ \ (shr, rps) ->
-                for_ rps $ \ (rp, vcs) ->
-                    putStrLn $
-                        "Found repo " ++
-                        shr ++ " / " ++ rp ++ " [" ++ show vcs ++ "]"
+        unless (repos == repos') $ liftIO $ do
+            putStrLn "Repo tree based on filesystem:"
+            printRepos repos
+            putStrLn "Repo tree based on database:"
+            printRepos repos'
+            throwIO $ userError "Repo dir check failed!"
+        liftIO $ printRepos repos
+        where
+        printRepos = traverse_ $ \ (shr, rps) ->
+            for_ rps $ \ (rp, vcs) ->
+                putStrLn $
+                    "Found repo " ++
+                    shr ++ " / " ++ rp ++ " [" ++ show vcs ++ "]"
     repoTreeFromDir = do
         dir <- askRepoRootDir
         outers <- liftIO $ listDirectory dir