The first Xcode 9 beta is now available! 
Notes: we’re still checking if everything’s working as expected, if you have any feedback please leave a comment below!
To select this Stack you just have to open your app on bitrise.io,
go to the Settings tab, and at the bottom of the Settings tab select the Xcode 9.0.x
stack option, and your next build will start on the Xcode 9.0 stack.
You can find the Stack’s full system report at:
https://github.com/bitrise-io/bitrise.io/blob/master/system_reports/osx-xcode-9.0.x.log,
and the changes/updates compared to the Xcode 8.3.2 stack at:
https://github.com/bitrise-io/bitrise.io/pull/144/commits/5615b96e09444b77e2686d64e8068fb01e20960a.
If you’d like to add additional tools to be pre-installed you can find the instructions on GitHub, for both the Linux and for the macOS stacks.
Information about Stack types & update schedules can be found here: discuss.bitrise.io/t/281.
Happy Building! 
