$ git clone -n https://src.fedoraproject.org/rpms/copr-rpmbuild.git /var/lib/mock/f42-build-side-1-3502131-45977/root/chroot_tmpdir/scmroot/copr-rpmbuild
Cloning into '/var/lib/mock/f42-build-side-1-3502131-45977/root/chroot_tmpdir/scmroot/copr-rpmbuild'...
$ git fetch origin 27b5a81c6ac64863f4f044af569cf306dae2878d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/copr-rpmbuild
 * [new ref]         27b5a81c6ac64863f4f044af569cf306dae2878d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 27b5a81 Update copr-rpmbuild to 1.3-1