$ git clone -n https://src.fedoraproject.org/rpms/bcunit.git /var/lib/mock/f38-build-side-42-init-devel-823965-28358/root/chroot_tmpdir/scmroot/bcunit
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-823965-28358/root/chroot_tmpdir/scmroot/bcunit'...
$ git fetch origin 5d4915fc55c52944591f33e24a6e9325988257c2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bcunit
 * [new ref]         5d4915fc55c52944591f33e24a6e9325988257c2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5d4915f Remove README.md.