$ git clone -n https://src.fedoraproject.org/rpms/R-qpdf.git /var/lib/mock/f38-build-725188-99560/root/chroot_tmpdir/scmroot/R-qpdf
Cloning into '/var/lib/mock/f38-build-725188-99560/root/chroot_tmpdir/scmroot/R-qpdf'...
$ git fetch origin 4de57c9048498b9d71ba4317db5915844ddeeafa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-qpdf
 * [new ref]         4de57c9048498b9d71ba4317db5915844ddeeafa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4de57c9 R-maint-sig mass rebuild