The engine -> framework roll failed on the changes to the --serve-observatory flag in https://dart.googlesource.com/sdk.git/+/fb1516c4ea52111f05a96d9eaedffc1e6feed000:

https://ci.chromium.org/ui/p/flutter/builders/try/Linux%20tool_integration_tests_4_4/20764/overview

cc @bkonyi @aam