We tried this:
```ruby
Appsignal::Transaction.create(SecureRandom.uuid, env)
Appsignal::Transaction.current.add_exception(env['rack.exception'])
Appsignal::Transaction.current.complete!
```
instead of this line. But then it only enqueues instead of actually sending the error. When we actually start the transaction in the call then Transaction.current is nil when we're in post_process. Might be due to some EM or Goliath magic, though we think it should work.

Any ideas?