Comment 4 for bug 1702960

Workaround until provided:
For a case like a MP at [1], which states on the LP page to do:
$ git clone -b artful-bind9-merge-9.10.3.dfsg.P4-12.6 https://git.launchpad.net/~ahasenack/ubuntu/+source/bind9

From that we take the user and the branch name for the steps you need:
user: ahasenack
branch: artful-bind9-merge-9.10.3.dfsg.P4-12.6

Instead do:
git ubuntu clone bind9
cd bind9
# user
git ubuntu remote add ahasenack
# branch
git checkout ahasenack/artful-bind9-merge-9.10.3.dfsg.P4-12.6

[1]: https://code.launchpad.net/~ahasenack/ubuntu/+source/bind9/+git/bind9/+merge/329548