$ git clone -n https://src.fedoraproject.org/rpms/php-sebastian-diff6.git /var/lib/mock/f42-build-3224796-41162/root/chroot_tmpdir/scmroot/php-sebastian-diff6
Cloning into '/var/lib/mock/f42-build-3224796-41162/root/chroot_tmpdir/scmroot/php-sebastian-diff6'...
$ git fetch origin b5f79798dfeade141da7bba30bee3121304ba46c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/php-sebastian-diff6
 * [new ref]         b5f79798dfeade141da7bba30bee3121304ba46c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b5f7979 enable test suite