Attach PDB to Nameko worker exceptions

attach_pdb.py

@pytest.yield_fixture
def pdb_worker_exceptions():
    import pdb
    from mock import patch
    from nameko.containers import ServiceContainer

    unpatched = ServiceContainer._worker_result

    def attach_pdb(self, worker_ctx, result, exc_info):
        if exc_info:
            pdb.post_mortem(exc_info[2])
        return unpatched(self, worker_ctx, result, exc_info)

    with patch.object(ServiceContainer, '_worker_result', new=attach_pdb):
        yield

You must run pytest with output capturing enabled (-s) in order to use this