Typical failures:

  Failed RemoteTest(iOS,"ios-arm64") [4 m 46 s]
  Error Message:
     Linker did not executed as expected.
  Expected: String containing "Building target "_RunILLink" completely."

2. NullReferenceException somewhere.

The first one seems to happen when rerunning the Windows tests job.

Diagnosis and improvements are in process:

• [devops] Don't allow re-running just the Windows tests job. #20116
• [devops] Split the re-enabling of the macOS bot for Windows tests to its own job. #20115
• [tests] Verify that we have a remote connection in tests that require a remote connection. #20114
• [msbuild] Add exception handling in the Copy task to track down random exception on the bots. #20100
• https://github.com/xamarin/Xamarin.Messaging/pull/709
• [devops] Terminate any existing builders and brokers when preparing Macs for remote testing. #20448

Issues filed:

• https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2045802
• https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2275459