How to change pinned packages in mamba package manager

Question

When I try to install a python package in a minimamba distribution (mamba 0.14), there is no dependency solution for the python version installed (shown as pinned package below). How can I allow this package to be downgraded to allow a dependency solution?

(base) C:\Users\user>mamba install nipy

(...)

Pinned packages:
  - python 3.9.4

Encountered problems while solving:
  - package nipy-0.4.1-py37hfa6e2cd_1001 requires python >=3.7,<3.8.0a0, but none of the providers can be installed

I have tried the --no-pin parameter with no changes.

What is a "Pinned package" in the first place? sorry for the noob question — Sky Scraper, Feb 07 '23 at 20:09
So that particular package at that specific version is required? @tiagoams — Sky Scraper, Feb 09 '23 at 17:54
@SkyScraper It is more the starting point, in this case python 3.9.4, for which a set of dependencies must be found. You might not need this python to be this version in which case see solutions below. — tiagoams, Feb 10 '23 at 14:03

score 6 · Accepted Answer · answered Jun 22 '21 at 08:10

6

Did you try mamba install python=3.7 nipy? This should downgrade python package to the required version allowing you to install nipy and its dependencies.

answered Jun 22 '21 at 08:10

qzn

76
1

I have accepted this solution as it solves the question, altough from @merv 's answer it seem not to be a good course of action when the pinned package is python itself. – tiagoams Jun 23 '21 at 09:22

score 5 · Answer 2 · answered Jun 22 '21 at 08:17

Changing a Python version in-place in a Conda environment has so many downsides (e.g., complicated solve; almost every package has to be redownloaded; risks breaking base) that whenever one requires a different Python version, the better thing to do is almost universally to create a new environment. Try instead

mamba create -n nipy_env nipy

How to change pinned packages in mamba package manager

2 Answers2