Consider propagating CI related env variables to the device

[vitek-karas]

The logic to filter out certain tests in dotnet/runtime relies on seeing some environment variables. One such example is SkipOnCIAttribute - it uses environment variables to detect if the test is running in CI:
https://github.com/dotnet/arcade/blob/82c695e89cef1fb20104a73f3ae281d0493d8275/src/Microsoft.DotNet.XUnitExtensions.Shared/Discoverers/SkipOnCIDiscoverer.cs#L21

We need to propagate the DOTNET_CI environment variable from the xharness tool environment to the test application on the device.

Without this the tests running on a Device behave differently from tests running on "desktop" directly.

For example, recently there are lot of failures in extra-platforms of the test MemoryStream_CapacityBoundaryChecks. Which is supposed to be disabled in all infra, but on devices it still runs and fails.

[vitek-karas]

@matouskozak @kotlarmilos for ideas

[vitek-karas]

After looking into this some more I think the correct fix is to modify how xharness is used by Arcade/Helix and pass the env. variables on the command line. It's a bit messy as Android and iOS uses different command line options to do this, but it's possible in both, and Aracade already has different handling of xharness for the two platforms anyway.

[kotlarmilos]

On iOS, XHarness is invoked in https://github.com/dotnet/runtime/blob/51359538882ae085c532442998e30fd1390dbcf6/eng/testing/tests.ioslike.targets#L36

For simulators, it is invoked in https://github.com/dotnet/arcade/blob/main/src/Microsoft.DotNet.Helix/Sdk/tools/xharness-runner/xharness-helix-job.apple.sh

For Android, it is invoked in https://github.com/dotnet/arcade/blob/main/src/Microsoft.DotNet.Helix/Sdk/tools/xharness-runner/xharness-helix-job.android.ps1

[vitek-karas]

The thing I was not able to track down (yet) is what env. variable is set by Helix in CI - the attribute reacts to 3 different variables, but I would prefer we only propagate the one which Helix actually uses...

[kotlarmilos]

I’ve invoked the CI https://dev.azure.com/dnceng-public/public/_build/results?buildId=1170370&view=results) with the DOTNET_CI environment variable set, to verify if that’s the one being used.

[kotlarmilos]

It is HELIX_WORKITEM_ROOT: --set-env=DOTNET_CI= --set-env=HELIX_WORKITEM_ROOT=/tmp/helix/working/BA6609A6/w/A9C109A8/e --set-env=AGENT_OS= --.

[kotlarmilos]

Tasks:

• iOS simulators (AOT on build machines): Add DOTNET_CI=true env variable to Apple and Android work item commands arcade#16213
• iOS devices (AOT on helix machines): [iOS] Fix SkipOnCI attribute support on Apple mobile devices runtime#120671
• Env variables support on Android: Add env variables support to Android test command #1481
• Android: TBD