[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.

[galpin]

Hi @rayluo,

Sorry for the slow response.

Unfortunately v0.20.0 results in a new error compared to 0.18.1, see below. Running in Ubuntu 22.04.5 LTS via WSL.

Let me know if you need anything else.

v0.18.1

> uv run -p 3.12 --with msal==1.34.0 --with pymsalruntime==0.18.1 repro.py
Using CPython 3.12.7
Removed virtual environment at: .venv
Creating virtual environment at: .venv
Installed 20 packages in 32ms
"{{\"ping\",\"success\"}}}"

v0.20.0

> uv run -p 3.12 --with msal==1.34.0 --with pymsalruntime==0.20.0 repro.py
Installed 11 packages in 15ms
Traceback (most recent call last):
  File "/home/galpin/r/rbauth/repro.py", line 7, in <module>
    app = PublicClientApplication(
          ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/msal/application.py", line 2046, in __init__
    super(PublicClientApplication, self).__init__(
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/msal/application.py", line 669, in __init__
    self._decide_broker(allow_broker, enable_pii_log)
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/msal/application.py", line 712, in _decide_broker
    _init_broker(enable_pii_log)
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/msal/application.py", line 31, in _init_broker
    from . import broker  # Trigger Broker's initialization, lazily
    ^^^^^^^^^^^^^^^^^^^^
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/msal/broker.py", line 14, in <module>
    import pymsalruntime  # Its API description is available in site-packages/pymsalruntime/PyMsalRuntime.pyi
    ^^^^^^^^^^^^^^^^^^^^
  File "/home/galpin/.cache/uv/archive-v0/humv0xhXhsbo5KXE5fkxs/lib/python3.12/site-packages/pymsalruntime/__init__.py", line 11, in <module>
    ctypes.CDLL(library_path)
  File "/home/galpin/.local/share/uv/python/cpython-3.12.7-linux-x86_64-gnu/lib/python3.12/ctypes/__init__.py", line 379, in __init__
    self._handle = _dlopen(self._name, mode)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: libwebkit2gtk-4.1.so.0: cannot open shared object file: No such file or directory
> 

[rayluo]

@galpin , thanks for the report, but please create a new github issue for it to be properly tracked. CC: @xinyuxu1026

[xinyuxu1026]

@galpin , pymsalruntime v0.20.0 does not come with libwebkitgtk bundled, the user needs to manually install it. Here is the documentation: https://learn.microsoft.com/en-us/entra/msal/python/advanced/linux-broker-py?tabs=ubuntudep#linux-dependencies