$ git clone -n https://src.fedoraproject.org/rpms/pdfgrep.git /var/lib/mock/f45-build-21491-586/root/chroot_tmpdir/scmroot/pdfgrep
Cloning into '/var/lib/mock/f45-build-21491-586/root/chroot_tmpdir/scmroot/pdfgrep'...
$ git fetch origin 968a853d5755bf054a283653537b58bad67d37f7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/pdfgrep
 * [new ref]         968a853d5755bf054a283653537b58bad67d37f7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 968a853 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild