See https://github.com/agda/agda/issues/2804

Index: b/src/full/Agda/Interaction/Library.hs
===================================================================
--- a/src/full/Agda/Interaction/Library.hs
+++ b/src/full/Agda/Interaction/Library.hs
@@ -308,7 +308,7 @@ getInstalledLibraries
   -> LibM [AgdaLibFile] -- ^ Content of library files.  (Might have empty @LibName@s.)
 getInstalledLibraries overrideLibFile = mkLibM [] $ do
     filem <- liftIO $ runExceptT $ getLibrariesFile overrideLibFile
-    case filem of
+    userlibs <- case filem of
       Left theOverrideLibFile -> do
         raiseErrors' [ LibrariesFileNotFound theOverrideLibFile ]
         return []
@@ -317,9 +317,15 @@ getInstalledLibraries overrideLibFile =
           ls    <- liftIO $ stripCommentLines <$> UTF8.readFile (lfPath file)
           files <- liftIO $ sequence [ (i, ) <$> expandEnvironmentVariables s | (i, s) <- ls ]
           parseLibFiles (Just file) $ nubOn snd files
+    systemlibs <- ifNotM (liftIO $ doesDirectoryExist systemLibDir) (return []) $ do
+      files <- liftIO $ filter isLibFile <$> listDirectory systemLibDir
+      parseLibFiles Nothing $ zip [1..] $ map (systemLibDir </>) files
+    return $ userlibs ++ systemlibs
   `catchIO` \ e -> do
     raiseErrors' [ ReadError e "Failed to read installed libraries." ]
     return []
+  where systemLibDir = "/var/lib/agda"
+        isLibFile fn = takeExtension fn == ".agda-lib" && not ("." `List.isPrefixOf` fn)
 
 -- | Parse the given library files.
 --
