$ git clone -n https://src.fedoraproject.org/rpms/rubygem-graphene1.git /var/lib/mock/f45-build-34942-692/root/chroot_tmpdir/scmroot/rubygem-graphene1
Cloning into '/var/lib/mock/f45-build-34942-692/root/chroot_tmpdir/scmroot/rubygem-graphene1'...
$ git fetch origin f464ef10a468558cc50d57cac91a972c3b63263a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-graphene1
 * [new ref]         f464ef10a468558cc50d57cac91a972c3b63263a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f464ef1 4.3.8 entry