CircleCI incident: Mac jobs failing to start

Affected components

• macOS Jobs

1. resolvedJun 1, 2026, 00:45 UTC

   Mac jobs have now fully recovered. Thank you for your patience during this incident.

2. monitoringJun 1, 2026, 00:42 UTC

   We have processed the backlog of Mac jobs and job start times are recovering to normal parameters.

3. monitoringJun 1, 2026, 00:24 UTC

   We are seeing Mac jobs starting successfully and improved network connectivity to the Mac fleet. We will continue to monitor the recovery.

4. identifiedMay 31, 2026, 22:38 UTC

   Mac jobs are continuing to experience failures. Our infrastructure provider is reporting they are experiencing a DDoS attack causing high network latency and packet loss for our Mac fleet. We are working to bring up additional capacity to restore service. We will continue to update as more information is available.

5. identifiedMay 31, 2026, 21:24 UTC

   We are continuing to investigate failures with Mac jobs starting due to high network latency and packet loss. Our engineers remain engaged with our infrastructure provider to restore service. We will provide another update within the hour, or sooner if circumstances change. We thank you for your patience while our engineers work to resolve this.

6. identifiedMay 31, 2026, 20:05 UTC

   We are still seeing failures with Mac jobs starting due to high network latency and packet loss. We will continue to update as we have more information on a resolution.

7. identifiedMay 31, 2026, 19:09 UTC

   We are continuing to work on resolving the networking issue for Mac jobs.

8. identifiedMay 31, 2026, 18:15 UTC

   We have identified a network outage that is preventing Mac jobs from starting. This include m4pro.medium and m4pro.large resource types. We are working with our infrastructure provider to restore service. We will update this incident as we work to resolve the issue.

What APIStatus.watch saw

Our 5-minute checks didn't record a change in CircleCI's overall status around this incident. Smaller or regional incidents often leave a provider's overall status green.

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How often does CircleCI have incidents?

CircleCI reported 22 incidents in the last 90 days, 1 of them major or critical. A typical incident lasted 1h 38m. See CircleCI's uptime and incident history