Setting transaction name doesn't work from child span.

Environment

How do you use Sentry? Sentry SaaS (sentry.io)

Which SDK and version? Python/Django: django-sentry-1.13.5, sentry-sdk-1.3.0 (also tried sentry-sdk-1.1.0)

Steps to Reproduce

We’re using Sentry in Django and Graphene (for GraphQL support). We would like to set the transaction name based on GraphQL operation name.

urlpatterns = [
    # ...snip
    path(
        'graphql',
        csrf_exempt(MyGraphQLView.as_view(graphiql=settings.GRAPHIQL_ENABLED)),
    ),
]

class MyGraphQLView(graphene_django.views.GraphQLView):
    def execute_graphql_request(
        self, request, data, query, variables, operation_name, show_graphiql=False
    ):
        with sentry_sdk.configure_scope() as scope:
            transaction_name = f'graphql.{operation_name}' # graphql.OperationName
            scope.transaction = transaction_name
            # This works:
            scope._span._containing_transaction.name = transaction_name
            return super().execute_graphql_request(
                request, data, query, variables, operation_name, show_graphiql
            )

From the trace view in Sentry, the GraphQLView span is nested several spans down (in Django middlewares). From my understanding of the sentry documentation: set transaction name It seems like the scope.transaction = 'name' setter should be enough, but doesn’t seem to work from child spans.

Expected Result

Sentry transaction name updated to graphql.OperationName.

Actual Result

Sentry transaction name stays as /graphql

[CoatedMoose]

I’m in the middle of some tasks and I can’t check right now, but will hopefully be able to later in the week.

[lobsterkatie]

Hi, @CoatedMoose. While you’re not wrong in your expectation, given the docs, making scope.transaction = new_name work means you’re relying on the weird type mismatch between the transaction getter and setter. Much better to do scope.transaction.name, both because it makes more sense and because it future-proofs you for the day when we finally fix that mismatch.

I’ll fix the docs to reflect this.