It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption to this rule, contact "@test-exemption-reviewer" in the #hackers channel in Chat (don't just cc them here, they won't see it! Use Discord!).

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing.

Thanks for digging in to this. I suspect it will be tricky to find all the places that need to be updated, but it is something that we need to get done. Please give a shout if you'd like any help tracking down any of the failures.

This is passing on CI now.

Are there any other checks that should be run before landing this?

In particular, I'd like to verify that RBE is working as intended.

Some of the CI engine builds took a long time to run (for example: https://ci.chromium.org/ui/p/flutter/builders/try/Mac%20Engine%20Drone/781285/overview, where a Mac host_debug_unopt build took 40 minutes). So I'm wondering if the change in build tool paths is affecting RBE.

The rbe configs pulled in the cipd package here https://github.com/flutter/engine/blob/main/DEPS#L982 have paths in them that need to be updated. You can get gclient sync to pull that cipd package by setting use_rbe: True in your .gclient file.

Updated the CIPD package and RBE looks like it's working now.