$ git clone -n https://src.fedoraproject.org/rpms/R-sysfonts /var/lib/mock/f39-build-1585671-38147/root/chroot_tmpdir/scmroot/R-sysfonts
Cloning into '/var/lib/mock/f39-build-1585671-38147/root/chroot_tmpdir/scmroot/R-sysfonts'...
$ git fetch origin 85fbac1ab8bdf0dcdc8eb2bd9f39a195ee418efd:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-sysfonts
 * [new ref]         85fbac1ab8bdf0dcdc8eb2bd9f39a195ee418efd -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85fbac1 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild