$ git clone -n https://src.fedoraproject.org/rpms/rust-rand_distr0.4 /var/lib/mock/f42-build-3453387-45488/root/chroot_tmpdir/scmroot/rust-rand_distr0.4
Cloning into '/var/lib/mock/f42-build-3453387-45488/root/chroot_tmpdir/scmroot/rust-rand_distr0.4'...
$ git fetch origin 8bf014b764da112351a85cdda3a6ec2617bd07aa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rand_distr0.4
 * [new ref]         8bf014b764da112351a85cdda3a6ec2617bd07aa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8bf014b Initial import (rand_distr 0.4 compat package)