#2651 fail quietly when removing a non-existing variable

[phreed]

This was discussed in issue #2651

When Powershell starts it runs the $PROFILE script.
micromamba init updates these profiles (e.g. $profile.CurrentUserAllHosts) with something like the following:

#region mamba initialize
# !! Contents within this block are managed by 'mamba shell init' !!
$Env:MAMBA_ROOT_PREFIX = "C:\Users\me\micromamba"
$Env:MAMBA_EXE = "C:\Users\me\.bin\micromamba.exe"
(& $Env:MAMBA_EXE 'shell' 'hook' -s 'powershell' -p $Env:MAMBA_ROOT_PREFIX) | Out-String | Invoke-Expression
#endregion

When run the following error is produced.

Remove-Variable:
Line |
   3 |  Remove-Variable MambaModuleArgs
     |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Cannot find a variable with the name 'MambaModuleArgs'.

The cause of the error is revealed by running the following command.

(& $Env:MAMBA_EXE 'shell' 'hook' -s 'powershell' -p $Env:MAMBA_ROOT_PREFIX) | Out-String

Which produces:

Import-Module "$Env:MAMBA_ROOT_PREFIX\condabin\Mamba.psm1" -ArgumentList $MambaModuleArgs
Remove-Variable MambaModuleArgs

While Mamba.psm1 accepts a missing/empty ArgumentList, the subsequent Remove-Variable on the undefined variable MambaModuleArgs produces the error.

I suspect the idea is that MambaModuleArgs is presumed to be set outside of the region mamba initialize. Therefore, I think the fix should accommodate that inten by changing the powershell shell hook...

Remove-Variable -Name MambaModuleArgs -ErrorAction SilentlyContinue

A related issue is that the documentation is weak on the purpose for MambaModuleArgs.

It is used in Mamba.psm1 and where seems to only have one defined entry.

$MambaModuleArgs = @{"ChangePs1"=$True};

[AntoinePrv]

Thanks

[AntoinePrv]

@phreed I am failing to push to this PR, cold you rebase?