frozen solving environment step in installing a package in ubuntu

Question

I am trying to install moose framework in my ubuntu ( 20.4 ). It has three main steps: exporting path of miniconda using:

export PATH=$HOME/miniconda3/bin:$PATH

Configuring Conda to work with conda-forge, and channel of developers of moose:

conda config --add channels conda-forge
conda config --add channels idaholab

and finally installing the framework using:

conda create --name moose moose-libmesh moose-tools

I tried it several times but I stuck in the solving environment step (version of my conda is also 4.8.3 ). I do appreciate if anyone help me to handle this problem.

Answer 1

Option 1: Use Mamba

That is a beast of an environment once it does eventually solve. Conda will struggle to solve it. I recommend using Mamba instead:

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

## create 'moose' env
mamba create -n moose moose-libmesh moose-tools

Option 2: Add Constraints

I was able to get Conda to solve it, but with some tweaks based on insights from what Mamba got. It still took several minutes to solve though. Here's the command that worked:

conda create -n moose -c idaholab -c conda-forge --override-channels moose-libmesh moose-tools python=3.7

That is, I use only the two channels (no defaults channel) and pre-specify that Python should be version 3.7. Sometimes leaving a Python dependency underspecified leads to a huge satisfiability problem and Conda just does not handle it well.