weird.hs

-- ghc 8.10.7

-- Server code
runServer ctx = do    
  bracket (spawnWorkers ctx) (mapM_ killThread) $ const    
    liftIO $ useContext ctx                             -- At this point context looks uninialized
  where
    spawnWorkers = replicateM (ctx ^. number) (fork $ worker ctx)

-- The code that works with optimization disabled but but don't with optimization enabled
-- ...    
ctx <- createCtx    
-- ...    
runServer ctx           
      
-- Those code snippets work regardless optimizations status
-- ...    
bracket createCtx freeCtx $ \ctx -> do
-- ...    
  runServer ctx           


-- ...    
ctx <- createCtx    
-- ...    
hanlde (h ctx) $ runServer ctx           
where
  h ctx@Ctx{..} (e::SomeException) = do
    log $ show ctx ^. member
    throwIO e