$ git clone -n https://src.fedoraproject.org/rpms/R-rprintf.git /var/lib/mock/f45-build-6373-348/root/chroot_tmpdir/scmroot/R-rprintf
Cloning into '/var/lib/mock/f45-build-6373-348/root/chroot_tmpdir/scmroot/R-rprintf'...
$ git fetch origin 79315679c653d84087303e75ac723ba9f9e44a59:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-rprintf
 * [new ref]         79315679c653d84087303e75ac723ba9f9e44a59 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7931567 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild