Dear Mandela, the first documentary from co-directors Dara Kell and Christopher Nizza, begins in chaos: Rubber bullets have been fired into a crowd of protesters in a South African township. These images are also the first lines of Dear Mandela’s mournful open letter to the man black South Africans, we are told by one such individual, think of as their Jesus Christ. Kell and Nizza take an indirect route to the heart of their story: the housing crisis faced by South Africa’s poor, many of whom have waited years for the house that Mandela built to build them their promised house. We meet several denizens of the “informal settlements” built outside of city centers and the young community organizers seeking to stop random and often brutal evictions. The suffering is undeniable, but the terms of this particular crisis take a while to become clear. Eventually the filmmakers follow a grassroots case contesting the 2008 “Slums Act,” whereby the African National Congress, in power for almost two decades now, allowed makeshift housing to be destroyed with impunity. Triumph follows tragedy as the case unfolds and history is caught repeating, but the larger, more complicated story underlying this brief but bracing missive still feels untold.