Describe the issue:

In an ipython shell, running the %pdb command turns on automatic pdb calling. If any later commands cause an exception to be raised, the debugger should be entered after the traceback is printed. If dask is imported, the debugger is no longer entered.

Minimal Complete Verifiable Example:

In an ipython shell:

In [1]: %pdb
Automatic pdb calling has been turned ON

In [2]: import dask

In [3]: raise ValueError("foo")
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[3], line 1
----> 1 raise ValueError("foo")

ValueError: foo

In [4]:

If dask is not imported, the debugger is entered as expected:

In [1]: %pdb
Automatic pdb calling has been turned ON

In [2]: raise ValueError("foo")
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[2], line 1
----> 1 raise ValueError("foo")

ValueError: foo
> <ipython-input-2-66d99343b0b5>(1)<module>()
----> 1 raise ValueError("foo")

ipdb>

Anything else we need to know?:

Environment:

• Dask version: This happens with versions 2023.6.1, 2023.7.0 and 2023.7.1. This does not happen with 2023.6.0
• Python version: 3.11.4
• Operating System: Debian Bookworm (in python:3.11.4 docker container running on macOS 13.5)
• Install method (conda, pip, source): pip