Understanding a LUCI build failure

31 builds failed:

windows/android_debug_arm64 (infra failure)

windows/android_profile_arm64 (infra failure)

windows/android_release_arm64 (infra failure)

windows/host_debug (infra failure)

windows/host_debug_unopt (infra failure)

windows/host_profile (infra failure)

windows/host_release (infra failure)

macos/ios_debug

macos/ios_debug_unopt

macos/ios_profile

macos/ios_release

macos/ios_debug_sim

macos/ios_debug_sim_arm64

macos/android_debug_arm64

linux/android_debug_arm64

linux/android_debug_unopt_arm64

macos/android_debug_unopt_arm64

macos/android_profile_arm64

linux/android_profile_arm64

macos/android_release_arm64

linux/android_release_arm64

macos/host_debug

macos/host_debug_unopt_arm64

macos/host_profile_arm64

macos/host_release_arm64

linux/host_debug

linux/host_debug_unopt

macos/host_profile

linux/host_profile

macos/host_release

linux/host_release