On January, 8th a maintenance will occur to upgrade existing OS X virtual machines. This operation aims to modify their material profile. This change is mandatory to allow the deployment of patch to support last versions of OS X.
Indeed, the Inria CI team developed a patch to CloudStack to support the very latest versions of Mac OS X. The patch will be deployed at the same time than the scheduled maintenance. Official Mac OS X 10.14 and 10.15 templates will be available a few weeks after the maintenance.
Also, the virtualization software we use is dropping the support for old OS X versions ( < 10.13). We are studying various options. One of the option is to upgrade existing VMs. If this option is a problem for you, please let us now by sending an email to email@example.com.
During the maintenance, your OS X virtual machines may be unavailable a few minutes (will be rebooted). To avoid problems, we encourage you to prevent builds on OS X slave during the maintenance (mark it as offline in Jenkins).