The behaviour changed in 3.8.0 to be inclusive of mincnt. However, that resulted in errors or warnings with some reduction functions, so now the default is to require at least 1 point to call the reduction function. This effectively restores the default behaviour to match that of Matplotlib 3.7 and before.

contour.allsegs, contour.allkinds, and contour.find_nearest_contour are no longer marked for deprecation.

To comply with requirements of setuptools_scm, the minimum version of setuptools has been increased from 42 to 64.