Support for Chained Exception Tracebacks

Is your feature request related to a problem? Please describe.

Being able to see the tracebacks for chained exceptions as a part of the stack trace in the NewRelic Errors UI is helpful for debugging issues in our code.

Currently, only the traceback for the most recent exception is considered when building error nodes. The traceback is extracted from sys.exc_info() in _observe_exception(...), then formatted by this call to exception_stack(...).

Feature Description

Ideally, exception_stack(...) should take in the value of the exception, then read and format the traceback from its __traceback__ attribute, concatenating it to the end of the formatted current stack. Additionally, it should follow the exception chain using the __context__ or __cause__ attribute on the exception while concatenating the formatted traceback of each exception along the way.

Describe Alternatives

Looking for suggestions.

Additional context

Here's a short example:

# foo.py

import newrelic.agent

def c():
    raise Exception("c")


def d():
    try:
        c()
    except Exception as e:
        raise Exception("d") from e


try:
    d()
except:
    newrelic.agent.notice_error()

Should report something like:

Traceback (most recent call last):
File "foo.py", line 17, in <module>
File "foo.py", line 13, in d
caused by: Exception('c')
Traceback (most recent call last):
File "foo.py", line 11, in d
File "foo.py", line 6, in c

Priority

Really Want

Start in newrelic/api/time_trace.py at _observe_exception(...) and newrelic/api/transaction.py at the exception_stack(...) call to trace how sys.exc_info() is currently formatted. Follow the requested traceback, context, and cause behavior, and consider the provided foo.py output the definition of done: the current and chained exception tracebacks appear in the reported stack.