Type of Request

infra task

Infrastructure Environment

Devicelab

What is happening?

Prerequisites

• Official macOS 15.5 release
• Run all flutter/flutter macOS tests manually on macOS 15.5 bot #167682
• Update .ci.yaml in flutter/flutter to use either macOS 14 or macOS 15 #167824
• Run all flutter/packages macOS tests manually on macOS 15.5+ bot #167822
• Update .ci.yaml in flutter/packages to use either macOS 14 or macOS 15 #167825
• Ensure no open issues in Tracking issue for any infra or test failures with macOS 15 #167681

Upgrade ~50% of bots to macOS 15.5 per arch per pool

• Always leave at least 20 bots per arch in the try and prod pools on macOS 14 to maintain beta/stable
  • The number 20 is determined by how many engine orchestrators there are that run macOS test (currently 10) and multiplied by 2 to be safe. This is to prevent resource deadlocking.
• beta/stable doesn't use staging so don't need to reserve bots in staging pool

Device lists:

• Try pool - arm64 bots
• Try pool - x86 bots
• Staging pool - arm64 bots
• Staging pool - x86 bots
• Prod pool - arm64 bots
• Prod pool - x86 bots

When ready to upgrade, file an issue with a list of explicit bots listed by name to upgrade. See b/326078082 as example. Include request to ensure the Flutter Devicelab cert is installed as well after reimage in the issue.

If something goes wrong or tests begin to fail, .ci.yaml changes from #167824, #167825 can be reverted if necessary.

Steps to reproduce

No response

Expected results

No response