Haskell build issue (Module `Language.Haskell.TH.Syntax' does not export `returnQ')

Question

at the moment I'm trying to write a small Haskell program but ran into a build problem.

My aim is to query a table in a sql srv DB.

Here my code :

{-# LANGUAGE OverloadedStrings #-}
module Main where

import Network.Socket (withSocketsDo)
import Control.Exception (bracket)

import Database.MSSQLServer.Connection
import Database.MSSQLServer.Query

main :: IO ()
main = do       
    let info = defaultConnectInfo { connectHost = "www"
                                  , connectDatabase = "xxx"
                                  , connectUser = "yyy"
                                  , connectPassword = "zzz"
                                  }
    withSocketsDo $
        bracket (connect info) close $ \conn -> do
        result <- sql conn "SELECT * FROM ProdData_" :: IO [ProdData]
        print result

data ProdData 
    = ProdData
        { mst_ID             :: Int
        , anl_ID             :: Int
        , nameMSt            :: String
        , anlageMst          :: String
        , maschinenID        :: String
        , maschine           :: String
        , maschinentyp       :: String
        , zeitstempel        :: UTCTime
        , auftrag            :: String
        , artikelnummer      :: String
        , werkzeug           :: String
        , sollmenge          :: Int
        , gutmenge           :: Int
        , ausschuss          :: Int
        , nester             :: Int
        , zykluszeit         :: Float
        , fortschrittProzent :: Float
        , verbleibendeZeit   :: Int
        } 
    deriving (Show)

If I now run 'cabal build' I get the following error :

src\Database\Tds\Primitives\Fixed.hs:87:36: error:
    Module `Language.Haskell.TH.Syntax' does not export `returnQ'
   |
87 | import Language.Haskell.TH.Syntax (returnQ)
   |                                    ^^^^^^^
cabal.exe: Failed to build ms-tds-0.4.0.1 (which is required by
exe:UpdateProdData from UpdateProdData-0.1.0.0). See the build log above for
details.

Has anyone an idea how I can resolve this issue ?

Regards, Sinan-David

Joseph Sible-Reinstate Monica · Accepted Answer · 2022-01-13T16:05:49.387

EDIT: This is now fixed as of ms-tds version 0.4.0.2. You should upgrade to that version if possible instead of using the below workarounds.

The problem is the ms-tds package uses returnQ instead of just return for some reason, which was never necessary for user code and was removed in GHC 9. This is something that should be properly fixed on their end, which I opened https://github.com/mitsuji/ms-tds/issues/1 about. In the meantime, there's two ways you can use this package anyway. The easier approach is to downgrade to GHC 8.10.7. Your other option is to download the source of that package, comment out that import, replace all returnQs with returns, and then set up Cabal to use your local copy of it, like this.

Haskell build issue (Module `Language.Haskell.TH.Syntax' does not export `returnQ')

1 Answers1