$ git clone -n https://src.fedoraproject.org/rpms/rust-z85.git /var/lib/mock/f42-build-3252936-41225/root/chroot_tmpdir/scmroot/rust-z85
Cloning into '/var/lib/mock/f42-build-3252936-41225/root/chroot_tmpdir/scmroot/rust-z85'...
$ git fetch origin 71cc0ec97fe50b2d2d2f884b7d307a08aad71c77:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-z85
 * [new ref]         71cc0ec97fe50b2d2d2f884b7d307a08aad71c77 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 71cc0ec Update to version 3.0.6; Fixes RHBZ#2343672