It's hard to debug errors in the sphinx agent

[alcarney]

Expected behavior

When an error occurs in the Sphinx agent, there is sufficient information in the logs to debug the issue

Actual behavior

Only the error message and a general location of the error are available

[esbonio.SphinxManager] Unable to start SphinxClient: Handler <function index_roles at 0x7fbd4ddad9e0> for event 'builder-inited' threw an exception (exception: Circular reference detected)
Traceback (most recent call last):
  File "/var/home/alex/Projects/swyddfa/esbonio/develop/code/bundled/libs/esbonio/server/features/sphinx_manager/client_subprocess.py", line 210, in start
    self.sphinx_info = await self.protocol.send_request_async(
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pygls.exceptions.JsonRpcInternalError: Handler <function index_roles at 0x7fbd4ddad9e0> for event 'builder-inited' threw an exception (exception: Circular reference detected)

Log output

No response

(Optional) Settings from conf.py

No response

[alcarney]

Configuring the agent to write logs to stderr should be enough to resolve this. The trick is figuring out a nice way to configure it via the parent language server