dumb http servers not supported

[justinsb]

Expected behavior

kpt should be able to clone from dumb http servers

Actual behavior

Fetching https://<foo>.storage.googleapis.com/kpt@main
fatal: dumb http transport does not support shallow capabilities
Error: Failed to execute git command "git origin origin --depth=1 main" against repo "https://<foo>.storage.googleapis.com/kpt" for reference "main" 

Details:
fatal: dumb http transport does not support shallow capabilities 

Information

Dumb http transports do not support shallow clones; we should likely retry with a non-shallow clone if the shallow clone fails. I don't know if there's a nice way to detect the error other than looking for a magic string.

Steps to reproduce the behavior

Try cloning a repo on a dumb http server; I can provide an example if needed!

[mortent]

Ideally we want to avoid relying on retries, as it means commands tends to be very slow and also complicates the UX. We currently pipe some of the output from git to the terminal to give users some more information about progress. Maybe there is a way we can check if the git remote is smart or dumb, and then choose the right approach on the first try. I haven't tried this out, but seems like there might be something we can do: https://stackoverflow.com/questions/9270488/is-it-possible-to-detect-whether-a-http-git-remote-is-smart-or-dumb/10661345