$ git clone -n https://src.fedoraproject.org/rpms/rbenv.git /var/lib/mock/f45-build-34341-684/root/chroot_tmpdir/scmroot/rbenv
Cloning into '/var/lib/mock/f45-build-34341-684/root/chroot_tmpdir/scmroot/rbenv'...
$ git fetch origin 8e5cddfe15c5578836f67c10936e3b1063c60db6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rbenv
 * [new ref]         8e5cddfe15c5578836f67c10936e3b1063c60db6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8e5cddf Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild