I have a TeamCity agent configured to build my XCode projects and I use github. I would like to automatically include in my release notes the descriptions from all pending commi
You could use the "Adding or Changing a Build Parameter from a Build Step" feature in order to update some build parameters right from a build step.
You would need a step which would call git log origin/master..master
(see "git: list commits not pushed to the origin yet"), after fetching from GitHub.
(See "Using Team City With Git " for the TeamCity configuration with GitHub, and make sure your TeamCity is runnig with the right account)