$ git clone -n https://src.fedoraproject.org/rpms/pdfmerge.git /var/lib/mock/f45-build-21501-586/root/chroot_tmpdir/scmroot/pdfmerge
Cloning into '/var/lib/mock/f45-build-21501-586/root/chroot_tmpdir/scmroot/pdfmerge'...
$ git fetch origin 29ee4ab7f0f20a88cde6ea1998168e2ad89b78e1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pdfmerge
 * [new ref]         29ee4ab7f0f20a88cde6ea1998168e2ad89b78e1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 29ee4ab Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild