Comment 0 for bug 1642699

https://code.launchpad.net/~gophers/golang/+git/golang is an import of https://go.googlesource.com/go, which is a gerrit instance with many thousands of changes. The log: (http://launchpadlibrarian.net/293800925/gophers-golang-+git-golang.log) shows launchpad importing each of these changes as a new branch, and then failing to send them to lp with "2016-11-17 11:37:11 INFO fatal: cannot exec 'send-pack': Argument list too long".

The Go team had similar problems with their syncing-to-github thing (https://github.com/golang/go/issues/16388), and afaict ended up hacking something up to push refs in batches (https://github.com/golang/build/commit/f2d63a86dd9cd149ab59a47b7ade41bb32d09b56) although comments also suggest that switching to git+ssh rather than git+https would have been enough (which I guess wouldn't be the easiest change ever for you to implement).