There was a single flake? I don't see what the issue is, but either way grt@ is the right person for installer these days.

Hmm, currently the waterfall looks green. Let me close this issue.

I just took a look at this failure:

https://build.chromium.org/p/chromium.win/builders/Win10%20Tests%20x64/builds/14338

It looks like chrome.exe was in use (i.e., couldn't be opened for exclusive access) when an update test was run:

AssertionError: In state 'chrome_user_updated_not_inuse', Value cmd of registry key HKEY_CURRENT_USER\Software\Chromium exists with value "C:\Users\chrome-bot\AppData\Local\Chromium\Application\62.0.3176.1\Installer\setup.exe" --rename-chrome-exe --verbose-logging

This likely means that AV or something on the bot was scanning the file. There's also this:

Exception: Could not uninstall Chrome. The installer exited with status 20.

That means that files were left behind on uninstall, likely for the same reason.

If this happens often enough we need to dig deeper to either relax the test expectations, make the installer try harder, or figure out what's really happening on the bot.

Feel free to re-open if it fails more.