$ git clone -n https://src.fedoraproject.org/rpms/buildbot.git /var/lib/mock/f41-build-side-1-2882797-34494/root/chroot_tmpdir/scmroot/buildbot
Cloning into '/var/lib/mock/f41-build-side-1-2882797-34494/root/chroot_tmpdir/scmroot/buildbot'...
$ git fetch origin 15e95def9431c68ef9c8b313f95af5cbb7811e03:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/buildbot
 * [new ref]         15e95def9431c68ef9c8b313f95af5cbb7811e03 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 15e95de 4.0.3