Try this

Author: michaelpj

lsp/src/Language/LSP/Server/Control.hs

@@ -19,6 +19,7 @@ import qualified Colog.Core as L
 import           Colog.Core (LogAction (..), WithSeverity (..), Severity (..), (<&), cmap)
 import qualified Control.Concurrent.Async as Async
 import           Control.Concurrent.STM.TChan
+import           Control.Concurrent (forkIO)
 import           Control.Monad.STM
 import           Control.Monad.IO.Class
 import qualified Data.Aeson as J
@@ -133,11 +134,11 @@ runServerWith ioLogger logger clientIn clientOut serverDefinition = do
         sendMsg
         recvMsg
 
+  _ <- forkIO serverIn
   -- Bind all the threads together so that any of them terminating will terminate everything
   _ <- Async.withAsync serverOut $ \a1 ->
-    Async.withAsync serverIn $ \a2 ->
       Async.withAsync processingLoop $ \a3 ->
-        Async.waitAny [a1, a2, a3]
+        Async.waitAny [a1, a3]
 
   ioLogger <& Stopping `WithSeverity` Info
   return 0