#173139 introduces an autoroller script that will build and run licenses_cpp when rolling dependencies.

It was quite an effort to get licenses_cpp building on that machine because we didn't have access to the docker images and the images are very minimal.

The setup we came up with is a bit precarious since it relies on us maintaining a is_minimal_linux GN argument, but we have no continuous integration that checks that it works beyond the autoroller itself. When the autoroller fails it isn't very obvious and our team doesn't have access to the error logs. So it's likely someone will break it in the future and it will be a pain to debug.

design

uploading

This pr has an example of building and uploading artifacts: https://github.com/flutter/flutter/pull/173131/files#diff-4c158154b6b3ee916c7fcef99ed0935054143056a316099377c08522351a07b9

downloading

We know what sha we are rolling into which can be used to derive the url for the prebuild licenses_cpp. The //.autoroller-preupload.sh script should be updated to download an execute that instead of building it.

considerations

• The autoroller image is x86_64, so we should be sure to cache that version
• licenses_cpp should be self contained so it should be just a matter of grabbing that exectuable.