$ git clone -n https://src.fedoraproject.org/rpms/plasma-nano.git /var/lib/mock/f42-build-side-1-3578405-46814/root/chroot_tmpdir/scmroot/plasma-nano
Cloning into '/var/lib/mock/f42-build-side-1-3578405-46814/root/chroot_tmpdir/scmroot/plasma-nano'...
$ git fetch origin 106de361227e8ebdeaa76542c294ad4a7804c289:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/plasma-nano
 * [new ref]         106de361227e8ebdeaa76542c294ad4a7804c289 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 106de36 6.4.1