Using grape integration throws uninitialized constant Datadog::Contrib::Rack::TraceMiddleware

[dim]

Manually adding the following line fixes the problem:

require 'ddtrace/contrib/rack/middlewares'

[delner]

I see... probably because we switched from a literal constant to a constant referenced in the Rack tracing middleware. This line of code here:

# set the request span resource if it's a `rack.request` span
request_span = payload[:env][Datadog::Contrib::Rack::TraceMiddleware::RACK_REQUEST_SPAN]

https://github.com/DataDog/dd-trace-rb/blob/master/lib/ddtrace/contrib/grape/endpoint.rb#L74

This didn't show up in our test suite because we loaded all constants there in the test environment.

Thanks for the report, we'll add this require to the Grape integration.

[delner]

This is being addressed in #533 . Should roll with 0.15.0.

[delner]

Merged to 0.15-dev, should roll today. Thank you @dim !