diff --git a/codex.cabal b/codex.cabal
--- a/codex.cabal
+++ b/codex.cabal
@@ -1,5 +1,5 @@
 name:                codex
-version:             0.4.0.2
+version:             0.4.0.4
 synopsis:            A ctags file generator for cabal project dependencies.
 description:
   This tool download and cache the source code of packages in your local hackage,
@@ -74,9 +74,10 @@
     , monad-loops         >= 0.4.2      && < 0.5
     , network             >= 2.6        && < 2.7
     , process
+    , transformers
     , wreq
     , yaml                
-    , codex               == 0.4.0.2
+    , codex               == 0.4.0.4
 
 source-repository head
   type:     git
diff --git a/codex/Main.hs b/codex/Main.hs
--- a/codex/Main.hs
+++ b/codex/Main.hs
@@ -8,6 +8,7 @@
 import Control.Arrow
 import Control.Exception (try, SomeException)
 import Control.Monad
+import Control.Monad.IO.Class (liftIO)
 import Control.Monad.Trans.Either hiding (left, right)
 import Data.Either
 import Data.List
@@ -93,7 +94,11 @@
       Source Tagged   -> return ()
       Source Untagged -> tags bldr cx i >> getTags s i
       Archive         -> extract hp i >> getTags s i
-      Remote          -> fetch s hp i >> getTags s i
+      Remote          -> liftIO $ eitherT ignore return $ fetch s hp i >> getTags s i
+        where
+          ignore msg = do
+            putStrLn $ concat ["codex: *warning* unable to fetch an archive for ", display i]
+            return ()
 
 help :: IO ()
 help = putStrLn $
diff --git a/src/Codex.hs b/src/Codex.hs
--- a/src/Codex.hs
+++ b/src/Codex.hs
@@ -14,6 +14,7 @@
 import Control.Monad.Trans.Either
 import Data.Machine
 import Data.Maybe
+import Data.List ((\\))
 import Distribution.Package
 import Distribution.Text
 import Distribution.Verbosity
@@ -128,9 +129,9 @@
     createDirectoryIfMissing True (packagePath root i)
     openLazyURI s url
   either left write bs where
-    write bs = fmap (const archivePath) $ tryIO $ BS.writeFile archivePath bs
-    archivePath = packageArchive root i
-    url = packageUrl i
+      write bs = fmap (const archivePath) $ tryIO $ BS.writeFile archivePath bs
+      archivePath = packageArchive root i
+      url = packageUrl i
 
 openLazyURI :: WS.Session -> String -> IO (Either String BS.ByteString)
 openLazyURI s = fmap (bimap showHttpEx (^. W.responseBody)) . try . WS.get s where
@@ -161,9 +162,16 @@
         tags'' tmp (WorkspaceProject id' sources) = taggerCmdRun cx sources tags''' where
           tags''' = tmp </> concat [display id', ".tags"]
     mergeTags files' o' = do
-      contents <- traverse TLIO.readFile files'
+      files'' <- filterM doesFileExist files'
+      contents <- traverse TLIO.readFile files''
+      case files' \\ files'' of
+        [] -> return ()
+        xs -> do
+          putStrLn "codex: *warning* the following tags files where missings during assembly:"
+          mapM_ putStrLn xs
+          return ()
       let xs = concat $ fmap TextL.lines contents
-      let ys = if sorted then (Set.toList . Set.fromList) xs else xs
+          ys = if sorted then (Set.toList . Set.fromList) xs else xs
       TLIO.writeFile o' $ TextL.unlines (concat [headers, ys])
     tags' = packageTags $ hackagePathOf bldr cx
     headers = if tagsFileHeader cx then fmap TextL.pack [headerFormat, headerSorted, headerHash] else []