$ git clone -n https://src.fedoraproject.org/rpms/rust-rand_distr /var/lib/mock/f42-build-3453388-45488/root/chroot_tmpdir/scmroot/rust-rand_distr
Cloning into '/var/lib/mock/f42-build-3453388-45488/root/chroot_tmpdir/scmroot/rust-rand_distr'...
$ git fetch origin fd2208090a8441a6c83bd22f09af879dd6a942a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-rand_distr
 * [new ref]         fd2208090a8441a6c83bd22f09af879dd6a942a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fd22080 Update to version 0.5.1; Fixes RHBZ#2346802