$ git clone -n https://src.fedoraproject.org/rpms/rust-cookie.git /var/lib/mock/f40-build-1910141-25079/root/chroot_tmpdir/scmroot/rust-cookie
Cloning into '/var/lib/mock/f40-build-1910141-25079/root/chroot_tmpdir/scmroot/rust-cookie'...
$ git fetch origin ddf512417224807a4b40ca52b43ac71fd1d18ef2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cookie
 * [new ref]         ddf512417224807a4b40ca52b43ac71fd1d18ef2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ddf5124 Update to version 0.18.1; Fixes RHBZ#2129682