notifications.webhooks using an encrypted url here https://github.com/ruby/ruby/blob/9948addda67f4b7a6e3575f1eba9025f998811d2/.travis.yml#L535-L539.
In recent failed builds like the following ones, it seems we didn’t receive requests to the webhook url:
According to Webhooks don't fire, I think I need you to take a look at the logs which are not visible on our side. Could you check notification logs of these builds?
FYI, the last webhook we successfully got was from https://travis-ci.org/github/ruby/ruby/builds/671188703 on Apr 5th.