Unable to grab references to uncaught exceptions

I work at Sentry, an open source software for application monitoring. We are adding support for Node+Cloud Functions to automatically report code errors. However, we are not able to get reference to the handler in order to capture uncaught exceptions. developers are required to manually catch the error and report it (https://github.com/GoogleCloudPlatform/stackdriver-errors-js#usage).

Here's current Sentry Node integration on Cloud Functions (https://docs.sentry.io/platforms/node/guides/gcp-functions/). This requires captureException call.

As a result of conversation with Steren and Vinod, posting the issue here.
cc: @steren @grant