$ git clone -n https://src.fedoraproject.org/rpms/rust-cookie_store.git /var/lib/mock/f40-build-1682211-24246/root/chroot_tmpdir/scmroot/rust-cookie_store
Cloning into '/var/lib/mock/f40-build-1682211-24246/root/chroot_tmpdir/scmroot/rust-cookie_store'...
$ git fetch origin a4cad6d232fbf91391e44d3add0e930139f25951:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cookie_store
 * [new ref]         a4cad6d232fbf91391e44d3add0e930139f25951 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a4cad6d Update to version 0.21.0; Fixes RHBZ#2263438