Conda install some-package hangs with (Solving environment: failed)

Question

I have tried multiple ways but can't conda install packages (in my case, geopandas). I tried geopandas install guide, but get output that the solver runs forever. I tried without creating an environment, after creating a new environment, using defaults channel and using conda-forge channel. None worked.

$ conda create -n top 
$ conda activate top
$ conda config --env --add channels conda-forge
$ conda config --env --set channel_priority strict
$ conda install python=3 geopandas

Collecting package metadata (current_repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.
Solving environment: failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): done
Solving environment: \ 

I don't want to use pip install because it is preferred to use conda install.

Also I tried installing using Anaconda Navigator following this answer, but the progress bar keeps hanging, saying "solving package specifications".

Answer 1

Favor Specifying Constraints at Creation

Iteratively installing packages is a real choking point for Conda. If you know up front that the env will require certain packages, then specify them at creation:

conda create -n top -c conda-forge -c defaults python=3 geopandas

This solves in seconds for me. If you have many packages, then use a YAML.

Use Mamba

Sometimes ad hoc installations are unavoidable. For tough solves (or just generally), try using mamba, a compiled (fast!) drop-in replacement for conda. Mamba will shine where Conda struggles.

# install mamba
conda install -n base conda-forge::mamba

# use mamba
mamba install -n top geopandas

Answer 2

After trying many advice from Conda's GitHub page, I found out that the issue was not being able to find dependencies for the python version I had installed. Creating new environment help but with one more argument for python version.

conda create -n branch-env python=3.7
conda activate branch-env
conda install geopandas