$ git clone -n https://src.fedoraproject.org/rpms/perl-JSON-Tiny.git /var/lib/mock/f45-build-24350-603/root/chroot_tmpdir/scmroot/perl-JSON-Tiny
Cloning into '/var/lib/mock/f45-build-24350-603/root/chroot_tmpdir/scmroot/perl-JSON-Tiny'...
$ git fetch origin ac716b82064f342f95b65e00119f5c5ce7dce801:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-JSON-Tiny
 * [new ref]         ac716b82064f342f95b65e00119f5c5ce7dce801 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ac716b8 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild