If you are just trying to install deep learning libraries in your environment then you can directly use an installer from here https://github.com/Esri/deep-learning-frameworks. You do not need to clone the environment in that case. However your environment cloning is failing due to some other reason. I recommend you to close all instances of ArcGIS Pro and Python command Prompt before doing so.
@SandeepKumar1, this is not a solution to the underlying problem. I am also experiencing this issue with ArcGIS Pro 2.8.1 when trying to clone the default arcgispro-py3 conda environment. Can esri provide an actual solution to this bug?
conda create --clone arcgispro-py3 --name arcgispro-py3-clone # ERROR conda.core.link:_execute(700): An error occurred while installing package 'esri::arcgis-1.8.5-py37_1783'.
I'm using 2.9.3 and also experiencing an issue cloning the default environment. The dialog won't go away after clicking OK a half hour ago. The list of errors I see when hovering over the octagonal exclamation point icon are long and extensive. Most of the errors mention jupyter in some capacity. I am unable to select and copy the text from the pop-up window for posting it with details here.