I installed miniconda via choco install miniconda3.
Creating a python3 environment works fine.
conda create --name envA python=3 --verbose
But creating a python2 environment has a problem.
conda create --name envB python=2 --verbose
Collecting package metadata (current_repodata.json): ...working... done
Solving environment: ...working... failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): ...working... done
Solving environment: ...working...
Found conflicts! Looking for incompatible packages.
failed
Traceback (most recent call last):
...
File "C:\Users\fred\miniconda3\lib\site-packages\conda\resolve.py", line 352, in find_conflicts
raise UnsatisfiableError(bad_deps, strict=strict_channel_priority)
conda.exceptions.UnsatisfiableError
@cel gets credit for this
Switching to mamba provided better diagnostics.
mamba create -n foo python=2
Looking for: ['python=2']
conda-forge/win-64 Using cache
conda-forge/noarch Using cache
Encountered problems while solving:
- nothing provides vc 9.* needed by python-2.7.12-0
Then use mamba to find vc.
mamba search vc
# Name Version Build Channel
vc 14.1 h21ff451_1 conda-forge
vc 14.1 h6d1b3ff_2 conda-forge
...
The vc v9 can be found in the defaults channel.
mamba search 'vc[channel=defaults]'
# Name Version Build Channel
vc 9 h2eaa2aa_6 pkgs/main
...
Updating the .condarc with the defaults channel, corrected the problem.
channels:
- conda-forge
- defaults
channel_priority: disabled
As a final note, should someone else find themselves in this situation...
The ~/.condarc got changed (dropping the defaults channel) as part of installing mambaforge.