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Unable to attach pdb remote debugger on MacOS #137033
Description
Bug report
Bug description:
When I try to attach a remote debugger on MacOS with:
python3.14 -m pdb -p 58653
I get the following error:
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/pdb.py", line 3610, in <module>
pdb.main()
~~~~~~~~^^
File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/pdb.py", line 3541, in main
attach(opts.pid, opts.commands)
~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Library/Frameworks/Python.framework/Versions/3.14/lib/python3.14/pdb.py", line 3425, in attach
sys.remote_exec(pid, connect_script.name)
~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: Cannot get task port for PID 58653 (kern_return_t: 5). This typically requires running as root or having the 'com.apple.system-task-ports' entitlement
The same thing happens also with sudo:
sudo python3.14 -m pdb -p 58653
or the root user:
sudo su
sh-3.2# python3.14 -m pdb -p 58653
I am able to get it to work by running the same command on Linux in Docker:
root@40505a05971f:/data# python -m pdb -p 13
> /data/remote_debugging.py(8)<module>()
-> time.sleep(1)
This is on MacOS Sequoia Version 15.5 and I'm using Python 3.14.0rc1 (b4 had the same issue though).
The release notes don't mention anything about this being a Linux only feature so I'm not sure if I'm doing something wrong or if this is an actual bug.
The script that I'm trying to attach to:
import os
import time
print(os.getpid())
counter = 1
while True:
counter += 1
time.sleep(1)CPython versions tested on:
3.14
Operating systems tested on:
macOS
Activity
ronaldoussoren commentedon Jul 23, 2025
I get the same with the python.org installer.
This appears to be related to notarization, likely a missing entitlement.
@ned-deily, com.apple.security.cs.debugger appears to be relevant here.
In particular:
That said, the documentation I link above says amongst others:
I didn't get this dialog during testing, but that was using an ad-hoc signature. The phrasing is worrisome because it doesn't mention if the dialog is only shown when using the restricted APIs. Getting a scary dialog when using python would be bad.
gaogaotiantian commentedon Jul 24, 2025
@pablogsal this is a
remote_execpermission issue.ned-deily commentedon Jul 24, 2025
Thanks for the report, @anze3db. And thanks for the analysis, @ronaldoussoren. I'll experiment with adding the debugger entitlement and report back.
@gaogaotiantian and @pablogsal, these kind of entitlement issues do not generally arise with ad hoc builds of Python and also likely not with some/most other third-party distributors of Python on macOS. They do arise with the python.org macOS installer because of the extra security hoops we have to go through (e.g. code signing, use of the hardened runtime, and code notarization) to be able to distribute Python via a downloadable installer that will meet Apple's Gatekeeper requirements. I'll also look into seeing if we need to document something.
ronaldoussoren commentedon Jul 24, 2025
It might be worthwhile to add a buildbot that add-hoc signs binaries using the the same settings as used by that installer. That would have caught this issue earlier, likewise for some LLDB debugging issues we had earlier. That said, this would add more complexity to the build with limited pay off.
Documenting this requirement would be nice, the entitlement is also needed for tools like pyinstaller and py2app if they want to generate app bundles that can be debugged using the remote debugger.
pablogsal commentedon Jul 24, 2025
See also the work here: #134290 .
We can add more information about this in the doc once we settle on something
ned-deily commentedon Aug 13, 2025
I've added the suggested entitlement to the macOS installer build for 3.14 and it appears to work nicely. I also tested using the remote debugger from a standard user account (not adminstrator) and, like @ronaldoussoren, I also did not get any authorization dialog; it just worked on both a current macOS 15.6 Apple Silicon Mac as well as on a 10.15.7 Intel VM. This additional entitlement will be in the upcoming 3.14.0rc2 macOS installer.
ned-deily commentedon Aug 13, 2025
FTR, the above test was done with both Pythons running under the same login session with the same user name. I subsequently tested with Pythons running under two different login sessions with different users, one a standard user and one an admin user. Attempting to bring up pdb from one user to debug a Python process running under the other failed in either direction with the above
PermissionErrorunless the pdb session was started from the admin user under sudo (i.e. with admin privilege enabled).ned-deily commentedon Sep 14, 2025
Since there have been no commets or complaints since 3.14.0rc2 was released, I am assuming this issue is now resolved.