Capturing call stack information

[JackKelly-Bellroy]

This may not be possible right now, but I wanted to log information that I found.

At time of writing, hal does not report a call stack on lambda errors:

hal/src/AWS/Lambda/RuntimeClient.hs

Line 225 in fc5318d

setRequestBodyLBS (encode (LambdaError { errorMessage = e, stackTrace = [], errorType = "User"}))

It would be nice if it did, but it's not obvious how with the current exception machinery. There's a trick but it probably means enumerating all known exception types with no obvious extensions, so maybe we consider this blocked until the decorate exceptions with backtrace information proposal is implemented, and gate that feature behind appropriate CPP?