This looks like a fairly challenging search. It may well be worth trying some commercial databases such as Sociological Abstracts or even Philosophers Index, to try to locate writings that take an anarchist approach to the Darfur situation.

I would be inclined to try quite anumber of web searches first, though - since this is a very current issue that is likely to attract much online comment from any anarchists who are concerned about how to confront a horrific situation when most other commentators simply recommend military force (UN, US, etc.).

Searching: anarchism sudan in the Google directory, http://www.google.com/dirhp , gets 32 hits, including an African anarchist site listed in a Stanford University list of African politics sources, http://library.stanford.edu/africa/poli1.html
This anarchism site, "Anarchism and Revolutionary Syndicalism in Africa" at: http://www.struggle.ws/africa.html leads to http://www.struggle.ws/africa/north.html which would include Sudan. But there is no obvious mention of Darfur in this page, and you could end up following many dead ends if you click on its other links.

A better approach seems to be to use CTRL-F (Edit-Find in page) on the long Stanford page, http://library.stanford.edu/africa/poli1.html, to search the names Darfur or Sudan. But it finds sites such as United States Institute of Peace (an institute set up by Congress) at http://www.usip.org USIP has a search feature that gets 104 hits on: Darfur, and it gets no hits if you add the word anarchism. Anarchy gets one hit out of the 104 that merely mentions the breakdown of order. It seems like a very long shot, but there COULD be useful anarchist writings on Darfur in those 32 hits in Google Directory for: sudan anarchism, or the 14 for: anarchist darfur, 16 for: anarchism darfur, etc. You have probably noticed that truncation in Google is inconsistent - anarchi* darfur gets zero hits in the Directory search.