$ git clone -n https://src.fedoraproject.org/rpms/rust-either.git /var/lib/mock/f41-build-59176444-6571500/root/chroot_tmpdir/scmroot/rust-either
Cloning into '/var/lib/mock/f41-build-59176444-6571500/root/chroot_tmpdir/scmroot/rust-either'...
$ git fetch origin c9cb1d71a81b1c894c2aa2890b63dcd389d4e3d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-either
 * [new ref]         c9cb1d71a81b1c894c2aa2890b63dcd389d4e3d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c9cb1d7 Update to version 1.15.0; Fixes RHBZ#2350206