We ran into the same MPL backend issue (TkAgg in our case) on our cluster. Using export DLClight=True worked for us as a work-around. For many reasons we'd prefer not to rely on users adding an environment variable. It seems simple enough to assume that headless DLC should be equivalent to the current DLClight, which defaults to MPL backend AGG.
We ran into the same MPL backend issue (TkAgg in our case) on our cluster. Using
export DLClight=Trueworked for us as a work-around. For many reasons we'd prefer not to rely on users adding an environment variable. It seems simple enough to assume that headless DLC should be equivalent to the current DLClight, which defaults to MPL backend AGG.