Weird output in powershell for commands tagged as preview.

[shenmuxiaosen]

az feedback auto-generates most of the information requested below, as of CLI version 2.0.62

Describe the bug
When I run CLI preview commands in Powershell script, the output messed up. It returned a message "Command group is in preview. It may be changed/removed in a future release" as expected but followed by a black chunk. It looks like the command hanged but actually it has return value just not able to see it in terminal. When I copied and pasted to notepad, I can see the expected return value.

Also when I started virtual environment and removed is_preview=True for the same command, the problem resolved. So I believe the preview help message somehow changed the Powershell background color or font color to be invisible in terminal.

To Reproduce
Run any preview CLI commands in Powershell. For example:
$x = $(az appconfig list -g YourResourceGroup)
Write-Host $x

This issue only happened when I run in a standalone Powershell script. It worked fine in Powershell ISE.

Expected behavior
It should return properly instead of a black chunk.

Environment summary
Windows-10-10.0.18362-SP0
Python 3.6.6
Shell: cmd.exe (PowerShell Core 6.2.4 64-bit)

azure-cli 2.0.80

Additional context
None

[arrownj]

Hi @jiasli , could you please help take a look at this ?

[yonzhan]

add to S166.

[jiasli]

Here is a similar screenshot of what is happening:

This is the same issue as #6080.

Root cause: #6080 (comment)
Fix (TODO): #6080 (comment)

[jiasli]

Without a proper fix from Colorama, we have added an option to disable color in #12604:

[Core] PREVIEW: Allow disabling color by setting AZURE_CORE_NO_COLOR environment variable to True or [core] no_color=True config (#12601)

[jiasli]

This issue has been fixed. Please see #6080 (comment) for the solution.