Fix accidental infinite loop in error message formatting

src/Vervis/Application.hs

@@ -50,6 +50,8 @@ import System.Log.FastLogger                (defaultBufSize, newStdoutLoggerSet,
 import Yesod.Default.Main                   (LogFunc)
 import Yesod.Mail.Send (runMailer)
 
+import qualified Data.Text as T (unpack)
+
 -- Import all relevant handler modules here.
 -- Don't forget to add new modules to your cabal file!
 import Vervis.Handler.Common
@@ -120,9 +122,9 @@ makeFoundation appSettings = do
             r <- migrateDB
             case r of
                 Left err -> do
-                    let msg = "DB migration failed: " <> msg
+                    let msg = "DB migration failed: " <> err
                     $logError msg
-                    error msg
+                    error $ T.unpack msg
                 Right (_from, _to) -> $logInfo "DB migration success"
 
     -- Return the foundation