[Bug] enable_broker_on_wsl prints pring to stdout

[galpin]

Describe the bug
Using the PublicClientApplication.enable_broker_on_wsl argument, the line "{{\"ping\",\"success\"}}} is written to stdout.

To Reproduce

from msal import PublicClientApplication


client_id = "REDACTED"
authority = "REDACTED"
scopes = [f"api://{client_id}/.default"]

app = PublicClientApplication(
    client_id=client_id,
    authority=authority,
    enable_broker_on_windows=True,
    enable_broker_on_wsl=True,
)
token = app.acquire_token_interactive(
    scopes=scopes,
    parent_window_handle=PublicClientApplication.CONSOLE_WINDOW_HANDLE,
)

Expected behavior
Nothing should be output to stdout.

What you see instead

> uv run repro.py
"{{\"ping\",\"success\"}}}"

The MSAL Python version you are using
1.33.0

[rayluo]

This is a known issue of the underlying PyMsalRuntime package. Assigning to @fengga and CC @ashok672 , @iulico-1

Also tracked internally at https://identitydivision.visualstudio.com/Engineering/_workitems/edit/3387107

[xinyuxu1026]

Acked. This is issue is addressed previously. Currently waiting for the next pymsalruntime release so that customer can adopt a new version which contains the fix.

[xinyuxu1026]

Hi @galpin , the fix is in pymsalruntime 0.20.0 (released 10/13/2025), could you please upgrade to this version and see if this is fixed? Thanks.

[rayluo]

Hi @galpin , the fix is in pymsalruntime 0.20.0 (released 10/13/2025), could you please upgrade to this version and see if this is fixed? Thanks.

Note that the PyMsalRuntime 0.20.0 was released after the latest MSAL Python 1.34.0, so, a pip install msal does NOT currently pick up PyMsalRuntime 0.20.0 by default, until we ship the next version of MSAL in the future. Meanwhile, @galpin you can manually do a pip install pymsalruntime==0.20.0 in your environment and see how that goes.