Fix CI job using GHC 8.6

Author: ethercrow

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
     - uses: haskell/actions/setup@v1
       with:
         ghc-version: ${{ matrix.ghc }}
-        cabal-version: '3.2'
+        cabal-version: '3.4'
     - name: Update cabal package database
       run: cabal update
     - name: Build
@@ -126,7 +126,7 @@ jobs:
     - uses: haskell/actions/setup@v1
       with:
         ghc-version: ${{ matrix.ghc }}
-        cabal-version: '3.2'
+        cabal-version: '3.4'
     - name: Update cabal package database
       run: cabal update
     - name: Build

megaexample/Main.hs

@@ -87,8 +87,7 @@ microservice httpRequestCounter = \req respond -> withSpan "handle_http_request"
     _ -> do
       bg_work <- async $ withSpan_ "background_task" do
         replicateM_ 3 $ do
-          tasks <- forM [1..5] (\i ->
-            async $ withSpan_ (BS.pack $ printf "task %d" (i :: Int)) $ threadDelay 10000)
+          tasks <- replicateM 5 (async $ withSpan_ "task" $ threadDelay 10000)
           mapM_ wait tasks
           threadDelay 10000
       addEvent sp "message" "started bg work"