Image: GitHub
Why it mattersAny CI workflow that still names macos-14, macos-14-large, or macos-14-xlarge will fail on specific dates in October before stopping altogether in November.
A workflow written a year ago that quietly reads runs-on: macos-14 is going to fail twice next week and then keep failing all month.
GitHub announced on October 1 that the macOS 14 runner image will be retired on November 2, 2026. The changelog lists three labels covered by the deprecation: macos-14, macos-14-large, and macos-14-xlarge. The replacement labels are macos-latest (currently macos-26), macos-15, macos-latest-xlarge (macos-26-xlarge), and macos-15-xlarge. All of these are macOS arm64 images.
The brownout schedule
To raise awareness ahead of the removal, GitHub will fail jobs that still use macOS 14 during eight scheduled windows this month. The windows, from the changelog:
- October 5, 14:00 UTC to October 6, 00:00 UTC
- October 12, 14:00 UTC to October 13, 00:00 UTC
- October 16, 14:00 UTC to October 17, 00:00 UTC
- October 19, 14:00 UTC to October 20, 00:00 UTC
- October 23, 14:00 UTC to October 24, 00:00 UTC
- October 26, 14:00 UTC to October 27, 00:00 UTC
- October 29, 14:00 UTC to October 30, 00:00 UTC
- October 30, 14:00 UTC to October 31, 00:00 UTC
GitHub also warns that macOS 14 runner capacity may be reduced in the lead-up to retirement, which could mean longer queue times for jobs that still use the deprecated labels even outside the brownouts.
What a team should do today
The changelog's "What you need to do" is a one-line migration: update workflow files to use macos-latest, macos-15, macos-latest-xlarge, or macos-15-xlarge. GitHub points to the runner images repository for up-to-date information about available tools and software on the new images, and tells teams who hit problems to contact GitHub Support.
The practical move for a team maintaining more than a few repositories is one grep across every .github/workflows/*.yml for the three retired labels, followed by a search of any shared Actions configuration (reusable workflows, composite actions, matrix definitions). An action that pins macos-14 in a release build is especially worth catching before October 5, because a failed release during a brownout is a Saturday nobody wants.
The migration cost is small for most teams: both macOS 15 and macOS 26 are arm64, and most tooling that works on macOS 14 arm64 works on them. The exception is a dependency version that was last updated to work with macOS 14 specifically, which is a smaller problem to find on October 5 than on November 2.
Source
This item was written by an AI system from the linked source. Reveneau is responsible for what it publishes.
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