No such comm: hv-extension-comm error in cmd prompt

The message ‘[IPKernelApp] WARNING | No such comm: hv-extension-comm’ has started appearing in my cmd prompt when trying to run a certain Jupyter notebook. However, it does not cause errors to appear in my browser console, and it does not stop the panel-based pipeline in the notebook from running correctly through all stages when prompted.

During the running of the same Jupyter notebook, I have started experiencing issues with visualizations using geoviews, so that images of shapefiles that previously appeared normally with the same code now appear blurry, are distorted, and show weird coloration. Therefore, I am making an initial assumption that the issue is related to the hv-extension-comm message that has started appearing in my cmd prompt.

The code that I am using to visualize is as follows near the end of a function:

shape_viz_p1 = gv.Shape.from_shapefile(self.file_param) shape_viz_p2 = datashade(shape_viz_p1, cmap=["blue"], precompute=True)* gvts.EsriImagery return pn.panel(shape_viz_p1)

The file path is valid (and I have tried using multiple shape files). The problem with the image being distorted occurs even in another notebook I am using that was previously producing a “normal” image. Also, the problem occurs regardless of whether or not I impose the overlay with EsriImagery.

No error message is produced in a traceback; the only indications of an issue are the message in the cmd prompt and the distorted image.

Please advise if you need any more info to assist. Thanks!

[WilliamBLeonard]

I see that the issue was previously mentioned in the now-closed issue of https://github.com/pyviz/holoviews/issues/3617, but no information is provided about what was done to resolve the issue there beyond the “solution” of placing code into another notebook.

[jbednar]

Open a PR to fix it and earn $500 🙂