runOnException does not run on asynchronous exceptions

We intend to instrument our use of DB connections by incrementing and decrementing a gauge through hooks,

let
    hooks' = hooks
      { runBefore = \conn mi -> do
          Stats.incGauge gauge
          runBefore hooks conn mi
      , runAfter = \conn mi -> do
          Stats.decGauge gauge
          runAfter hooks conn mi
      , runOnException = \conn mi e -> do
          Stats.decGauge gauge
          runOnException hooks conn mi e
      }

We find that the gauge tends to just keep incrementing over time, as if there are cases where we increment but never decrement.

Our best theory is that when a web request times out (using timeout), the asynchronous exception does not result in runOnException firing.

That means when our DB is overloaded, our connection pools start to get exhausted, and we begin timing out requests, our active-connections metric goes sideways -- exactly when we'd want to use it.

The code seems to support that:

runSqlPoolWithExtensibleHooks r pconn i SqlPoolHooks{..} =
    withRunInIO $ \runInIO ->
        withResource pconn $ \conn ->
            UE.mask $ \restore -> do
                conn' <- restore $ runInIO $ alterBackend conn
                _ <- restore $ runInIO $ runBefore conn' i
                a <-
                    restore (runInIO (runReaderT r conn'))
                        `UE.catchAny` \e -> do -- <-- HERE
                            _ <- restore $ runInIO $ runOnException conn' i e
                            UE.throwIO e
                _ <- restore $ runInIO $ runAfter conn' i
                pure a

The use of UniftIO.Exception.catchAny means only synchronous exceptions would be caught. Others, such as Timeout, would never result in runOnException firing.

Can this be changed to also catch and rethrow asynchronous exceptions? I know handling asynchronous exceptions can be Bad, but I wonder if given the likely use case of a web server, where the main process is almost never going to die (the usual way a missed cleanup finally gets dealt with), perhaps guaranteeing runOnException runs is more important.

Start at runSqlPoolWithExtensibleHooks, especially the UE.mask and UE.catchAny block marked HERE, and trace how timeout exceptions propagate through the hook sequence. Verify the behavior for asynchronous exceptions and define done as ensuring the intended exception hook behavior without breaking cleanup or rethrowing semantics.