$ git clone -n https://src.fedoraproject.org/rpms/efivar.git /var/lib/mock/f40-build-1944987-25179/root/chroot_tmpdir/scmroot/efivar
Cloning into '/var/lib/mock/f40-build-1944987-25179/root/chroot_tmpdir/scmroot/efivar'...
$ git fetch origin e06c32801702915e01e90fdd6a7cae6a0c70967d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/efivar
 * [new ref]         e06c32801702915e01e90fdd6a7cae6a0c70967d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e06c328 Turns out we need the abixml update in rawhide only, not f40.