Egypt should push Haftar to reconcile with the government in Tripoli. If a unified government is achieved and civil war comes to an end, it is a win-win situation for Libyans and everyone else.
If he refuses, wash your hands off with him and close your border. Supporting warlords will only increase the suffering of Libyans and insecurity in the region.
One important lesson from conflicts in Somalia and Libya: Never support the overthrow of an existing government through violent means. Oncer you remove it, it is very difficult to put it back together. There is also a Hadith that warned us no to start an uprising against a ruler unless he denies us (Muslims) from performing the required daily prayers. This is where we got it wrong in many conflicts throughout the Muslim world.