Micromamba cannot find python on Windows

[arthursw]

Troubleshooting docs

• My problem is not solved in the Troubleshooting docs

Anaconda default channels

• I do NOT use the Anaconda default channels (pkgs/* etc.)

How did you install Mamba?

Micromamba

Search tried in issue tracker

No entries matching "python" found

Latest version of Mamba

• My problem is not solved with the latest version

Tried in Conda?

Not applicable

Describe your issue

I did the following steps:

• download micromamba,
• renamed it to micromamba.exe,
• Invoke the hook with .\micromamba.exe shell hook -s powershell | Out-String | Invoke-Expression
• created an env with micromamba create -n test and activate it with micromamba activate test
• search for python with mircromamba search python

This gave me the following error:

(test) PS C:\project\micromamba> micromamba search python
Getting repodata from channels...

conda-forge/noarch                                  17.7MB @  10.0MB/s  1.8s
conda-forge/win-64                                  26.1MB @   9.8MB/s  2.6s
No entries matching "python" found
Try looking in a different channel with '--channel'.

Any idea why?

Here is my only config file:

(test) PS C:\project\micromamba> cat C:\Users\ci\.condarc
channels:
  - conda-forge
channel_priority: flexible

I deleted the only existing package cache folder.

The error also occurred when I installed with Invoke-Expression ((Invoke-WebRequest -Uri https://micro.mamba.pm/install.ps1).Content).

The weirdest thing is that I did manage to use micromamba on this machine today ; all the following commands used to work:

Invoke-Webrequest -URI https://github.com/mamba-org/micromamba-releases/releases/download/2.0.4-0/micromamba-win-64 -OutFile micromamba.exe
Set-Location -Path "C:\project\micromamba"
$Env:MAMBA_ROOT_PREFIX="C:\project\micromamba"
.\micromamba.exe shell hook -s powershell | Out-String | Invoke-Expression
micromamba config append channels conda-forge
micromamba config append channels nodefaults
micromamba config set channel_priority flexible
micromamba create -n project python=3.10.8 -y
micromamba activate project
micromamba install "zeroc-ice==3.6.5" -y
pip install "omero-py==5.15.0" "simpleitk>=2.3.1, <2.4"

mamba info / micromamba info

(test) PS C:\project\micromamba> micromamba info

       libmamba version : 2.0.4
     micromamba version : 2.0.4
           curl version : libcurl/8.8.0-DEV Schannel zlib/1.3.1
     libarchive version : libarchive 3.7.2 zlib/1.3.1 liblzma/5.6.2 bz2lib/1.0.8 liblz4/1.9.4 libzstd/1.5.6
       envs directories : C:\Users\ci\AppData\Roaming\mamba\envs
          package cache : C:\Users\ci\AppData\Roaming\mamba\pkgs
                          C:\Users\ci\.mamba\pkgs
                          C:\Users\ci\AppData\Roaming\.mamba\pkgs
            environment : test (active)
           env location : C:\Users\ci\AppData\Roaming\mamba\envs\test
      user config files : C:\Users\ci\.mambarc
 populated config files : C:\Users\ci\.condarc
       virtual packages : __win=10.0.19045=0
                          __archspec=1=x86_64
               channels : https://conda.anaconda.org/conda-forge/noarch
                          https://conda.anaconda.org/conda-forge/win-64
       base environment : C:\Users\ci\AppData\Roaming\mamba
               platform : win-64

Logs

(test) PS C:\project\micromamba> micromamba search python
Getting repodata from channels...

conda-forge/noarch                                  17.7MB @  10.0MB/s  1.8s
conda-forge/win-64                                  26.1MB @   9.8MB/s  2.6s
No entries matching "python" found
Try looking in a different channel with '--channel'.

environment.yml

I have no environment.yml.

~/.condarc

$ cat ~/.condarc
channels:
  - conda-forge
channel_priority: flexible
(test)

[arthursw]

I think running micromamba env update solved the problem. I think this comes from the fact that I didn't have a default base environment.

Why is the base environment necessary?

[arthursw]

My bad, running micromamba env update does not help. I'll continue investigating this error.

[arthursw]

I compared the cache on two machines (one where micromamba cannot find python, one where it can) with the following script:

from pathlib import Path
import json

cache = Path('C:\\Users\\amasson\\AppData\\Roaming\\mamba\\pkgs\\cache')
# cache = Path('C:\\Users\\ci\\AppData\\Roaming\\mamba\\pkgs\\cache')

for file in sorted(list(cache.glob('*.json'))):
    print(file)
    with open(file, 'r') as f:
        content = json.load(f)
        if 'packages' not in content: continue
        pys = [p for k, p in content['packages'].items() if p['name'] == 'python']
        kys = [k for k, p in content['packages'].items() if p['name'] == 'python']
        print(len(pys))
        del content['packages']
        del content['packages.conda']
        for k in kys:
            if k in content['removed']:
                print(f'The python {k} is in removed!')
        if 'removed' in content:
            del content['removed']
        print(content)
    print('\n\n')

and they both contain 229 python entries:

C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\1f08abba.json
229
{'info': {'subdir': 'win-64'}, 'repodata_version': 1}

C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\1f08abba.state.json
C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\64c641e7.json
0
{'info': {'default_numpy_version': '1.7', 'default_python_version': '2.7', 'platform': 'win', 'arch': 'x86_64', 'subdir': 'win-64'}}

C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\64c641e7.state.json
C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\758dc0ed.json
0
{'info': {'default_numpy_version': '1.7', 'default_python_version': '2.7', 'platform': None, 'arch': None, 'subdir': 'noarch'}}

C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\758dc0ed.state.json
C:\Users\amasson\AppData\Roaming\mamba\pkgs\cache\eb045dd1.json
0
{'info': {'subdir': 'noarch'}, 'repodata_version': 1}

So I don't understand why in one case micromamba says No entries matching "python" found.

[arthursw]

It might be due to a out-of-memory error, since I got the following message:
Out of memory allocating 56623104 bytes!

However, this error does not appear all the time.

Yet, the command works when I free some memory on my system.