I got multiple LUCI failures for one of my PRs. One of them seems like an error with a git command. The other one couldn't find vpython for some reason.

PR: flutter/engine#20278

LUCI failures:

• https://ci.chromium.org/p/flutter/builders/try/Mac%20Android%20AOT%20Engine/6610
• https://ci.chromium.org/p/flutter/builders/try/Mac%20Web%20Engine/7490