az login hangs on WSL

[gxtaillon]

Describe the bug

Running az login hangs, no output is shown. This is on Debian 10 over WSL on Windows 1809.

Running az login --debug logs the following link, opening manually and logging in works fine.
Open browser with url: https://login.microsoftonline.com/common/oauth2/authorize?....

Command Name
az login

Errors:
None

To Reproduce:

Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

• az login

Expected Behavior

The browser opens.

Environment Summary

Linux-4.4.0-17763-Microsoft-x86_64-with-debian-10.4
Python 3.6.10
Installer: DEB

azure-cli 2.9.1

Additional Context

[yonzhan]

add to S174

[jiasli]

I tried Debian WSL on Microsoft Store but couldn't repro.

The code for opening a browser is at

azure-cli/src/azure-cli-core/azure/cli/core/util.py

Line 526 in 0421019

return subprocess.call(['powershell.exe', '-Command', 'Start-Process "{}"'.format(url)])

Does it work if you run powershell.exe in WSL? It should print something like

$ powershell.exe
Windows PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

Try the new cross-platform PowerShell https://aka.ms/pscore6

PS Microsoft.PowerShell.Core\FileSystem::\\wsl$\Debian\home\user3>

But indeed, the current az login process for auth code flow gives too little information and sometimes leads to confusion, as discussed in MicrosoftDocs/azure-docs-cli#2093.

[gxtaillon]

@jiasli Running this spins up the loading icon on the mouse for about half a second, and then nothing happens.

gtaillon@debian:/mnt/c/Users/gtaillon$ powershell.exe -Command Start-Process "https://google.com"
gtaillon@debian:/mnt/c/Users/gtaillon$ which powershell.exe
/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe

However this works (from PowerShell/PowerShell#5715 (comment)):

[System.Diagnostics.Process]::Start([System.Diagnostics.ProcessStartInfo] @{ FileName = 'http://example.org'; UseShellExecute = $True })

That powershell is 5.1.17763.x