$ git clone -n https://src.fedoraproject.org/rpms/thunderbird.git /var/lib/mock/f43-build-60944965-6586536/root/chroot_tmpdir/scmroot/thunderbird
Cloning into '/var/lib/mock/f43-build-60944965-6586536/root/chroot_tmpdir/scmroot/thunderbird'...
$ git fetch origin a11ae8fff78401072ab6d829d5a456835d159496:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/thunderbird
 * [new ref]         a11ae8fff78401072ab6d829d5a456835d159496 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a11ae8f Update to 128.12.0