Xcode 8.3 was released on March 27, and as of yesterday we officially support it for your macOS builds on CircleCI.

What’s new in 8.3? Xcode 8.3 is a maintenance update with bug fixes and performance improvements. It improves iOS simulators and test stability.

To enable 8.3 in your builds, add the following to your circle.yml:

machine: 
  xcode:
    version: 8.3

We’ve also recently open sourced our image tests for macOS, which you can find here: https://github.com/circleci/macos-image-tests

If you think there’s something we can do to improve our tests for our images, we’d welcome your contributions.

In addition, you can see our image tests running here: https://circleci.com/gh/circleci/macos-image-tests

Oh, and one more thing: we’ll never force you to change your image again. We now support opt-in upgrades for macOS.

When building iOS and Mac projects, you can now easily choose when you would like to upgrade to a newer build image and Xcode version. Gone are the days when we automatically changed images for you, therefore breaking your builds. All new changes will be introduced in new images, together with new Xcode versions.

Going forward, when we release a new build image, our plan is to make small updates to it in the first two weeks in response to your feedback. After that we intend to only update the image when absolutely necessary, for example in the case of security updates.

This also allows us to add support for newer Xcode versions more quickly than before. Previously, we had been using a monolithic build image with multiple Xcode versions preinstalled. This update changes that to multiple images, each with a single version of Xcode installed.

For more on this update, and to share feedback with our team, see our Discuss post here.

And, check out our post on 5 great OSS tools for mobile developers.