$ git clone -n https://src.fedoraproject.org/rpms/emacs-vm.git /var/lib/mock/f41-build-side-1-2893042-34611/root/chroot_tmpdir/scmroot/emacs-vm
Cloning into '/var/lib/mock/f41-build-side-1-2893042-34611/root/chroot_tmpdir/scmroot/emacs-vm'...
$ git fetch origin 77ae8529d38c147db92a259d14e6dd3329f4b814:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/emacs-vm
 * [new ref]         77ae8529d38c147db92a259d14e6dd3329f4b814 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 77ae852 Upgrade to latest snapshot.