Conda debug

conda-debug.md

If conda install hangs on "solving environment," it typically means that Conda is taking a long time to resolve dependencies for the requested package(s). This can happen for several reasons:

Common Causes:

1. Complex Dependency Graph:

   • The requested package has many dependencies, and Conda is trying to find a compatible set of versions for all packages in the environment.

2. Large Environment:

   • If your environment already has many installed packages, resolving dependencies can take longer.

3. Outdated Conda:

   • Older versions of Conda may have slower dependency resolution algorithms.

4. Slow or Unresponsive Channels:

   • Conda may be trying to fetch metadata from slow or unreachable channels.

5. Conflicting Dependencies:

   • The requested package may have version conflicts with existing packages in the environment.

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Solutions:

1. Update Conda:

   • Update Conda to the latest version, which often includes performance improvements:

     conda update conda

2. Use the --freeze-installed Flag:

   • This tells Conda to avoid upgrading or downgrading already installed packages, reducing the complexity of dependency resolution:

     conda install <package_name> --freeze-installed

3. Use the mamba Solver:

   • mamba is a faster drop-in replacement for Conda's dependency solver:

     conda install mamba -n base -c conda-forge
     mamba install <package_name>

4. Specify Package Versions:

   • Providing specific versions for the package and its dependencies can help Conda resolve the environment faster:

     conda install <package_name>=<version>

5. Clear Conda Cache:

   • Clear Conda's package cache to ensure metadata is up-to-date:

     conda clean --all

6. Check Channel Configuration:

   • Ensure that your channels are correctly configured and prioritize faster channels like conda-forge:

     conda config --show channels
     conda config --add channels conda-forge

7. Create a New Environment:

   • If the current environment is too complex, consider creating a new one:

     conda create -n new_env <package_name>

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Debugging:

If the issue persists, you can enable verbose output to see where Conda is getting stuck:

conda install <package_name> -vvv

This will provide detailed logs that can help identify the root cause.