Hi @zhaleh-safikhani , Thanks for the heads up! I've checked and this new version seems to still be unstable (I cannot seem to make matplotlib.cm.ColormapRegistry.get_cmap work) so I'll wait until ...

Bug summary Hello, while packaging 3.5.0rc1, i notice that it's no longer possible to set a custom matplotlibrc, if the default one is "invalid".