Updating to mamba 2.0.5 breaks the default Miniforge installation in Windows

[alex180500]

As mentioned here conda-forge/miniforge#703 updating the latest miniforge version (which is the recommended way to install mamba) breaks the base environment and other stuff.

Steps to reproduce:

1. Fresh install of 24.11.0 Miniforge for windows (ships with mamba 1.5.12)
2. mamba update --all on the base environment from miniforge shell

[jjerphan]

Do you mean that your environment list is not shown?

[alex180500]

There are multiple problems (as listed here conda-forge/miniforge#703):

1. The environment list is broken as it shows a blank active environment and a base environment although I should only have the base environment active.
   
2. Updating with mamba update on the base environment emits a line of gibberish that is sent to powershell
   
3. mamba shell init powershell should rewrite older mamba init in the powershell profiles

[kuepe-sl]

The "glibberish" is caused by mamba update mamba modifying the condabin\mamba.bat file during the update. (changes see 651622b#diff-c62908c4dda4e1447bacf6739e9d7e22210cfd907b9ce81019b95726196dfde9)
After the update, cmd.exe tries to resume executing the .bat file and due to the changed content it tries to execute random text.

To make things worse, the errors cause a return code of 1 and thus any Mamba update from 1.x to 2.x in a CI system will fail.

[Klaim]

These changes are necessary for shell init to work correctly (in the case of cmd), however we didnt consider that an update command would be able to, as part of it's applied modifications, run that shell init, which (now obviously) happens when the package is mamba itself...
Looking for a solution 👍🏽 Right now updating mamba that way was silently broken because it assumed that shell scripts never change.

[jjerphan]

@kuepe-sl and @alex180500: would you be free for a call in the coming days so that we can better understand your setup the problems you are having?

[alex180500]

I'm not available for calls in this period but the steps to reproduce are:

1. Fresh install of 24.11.2-1 Miniforge for windows (ships with mamba 1.5.12) downloading Miniforge3-24.11.2-1-Windows-x86_64.exe. Simple default installation.
2. From Miniforge prompt mamba update --all (which updates mamba from 1.5.12 to 2.0.5) then yes

Just after these steps: