Cannot define a blueprint-specific exception handler

Describe the bug The documentation at https://sanicframework.org/en/guide/best-practices/blueprints.html#exceptions says that:

Just like other exception handling, you can define blueprint specific handlers.

However, exception handlers defined this way don’t seem to be blueprint-specific at all. Instead, they handle exceptions in other blueprints as well.

Code snippet

#!/usr/bin/env python3

from sanic import Sanic, Blueprint, response

class Error(Exception):
    pass

handled = Blueprint("handled")
@handled.exception(Error)
def handle_error(req, e):
    return response.text("handled {}".format(e))

b = Blueprint("b")
@b.route("/")
def e(request):
    raise Error("error in e")

app = Sanic(__name__)
app.blueprint(handled)
app.blueprint(b)
app.run()

Expected behavior A request to http://localhost:8000 should generate 500, because Error should not be handled. Instead, the request generates 200, Error is handled, even though the handler is registered in handled, while the endpoint is in b.

Environment (please complete the following information):

• OS: ubuntu 19.10
• Version: Sanic 21.6.0; Routing 0.7.0

Additional context The order of blueprint registration does not seem to change anything. Not registering blueprint handled obviously fixes the issue.

Is it a bug or am I missing something here?

[ahopkins]

See #2246 with a fix to this.

[komar007]

Thanks,

it works as expected.

The code from the OP is indeed not a sensible use case, just the simplest reproduction path.