%debug magic does not work repeatably for untitled files

[madphysicist]

What steps reproduce the problem?

1. Create a simple file with a single cell with like this:

   #%% define foo
   def foo(bar):
       x = ['a']
       for i in range(100):
           x.append(i + 3)
       return x
   

2. Execute the file using the green arrow:

   runfile('.../test.py', wdir='...')
   

3. Place a breakpoint in line 4:
   

4. Run a %debug magic on foo with any argument:
   

   Enters debugging normally:
   

5. Quit debugging (or step through) and try again

   
   

   Only "s" appears to work, and pressing "c" ignores the breakpoint entirely:

   

Expected Behavior

I expect %debug to work twice, especially when I don't modify the file.

Attempted solutions:

1. Rerun the file:
   
   Does not work
2. Modify the file, save it, then rerurn and attempt to debug. Output shows that the modification propagated to the foo in the console:
   
   
   Does not work.
3. Clear all variables. Does not work.
4. Restart kernel (or IDE). That works as expected every time. But doesn't seem like that's a very good solution.

Comment

The reason that I mention cells in the example is that ideally, I would like to reload my code by running the cell rather than the entire file. The files I have at the moment are sort of like notebooks that I am using the cell functionality to run. I would love not to have to reload the entire file (mush less the kernel), every time I made a change just to the function I'm trying to debug.

Versions

• Spyder version: 4.1.5
• Python version: 3.8.8 (default, Apr 13 2021, 15:08:03) [MSC v.1916 64 bit (AMD64)]
• Qt version: 5.9.7
• PyQt version: 5.9.2
• Operating System name/version: Windows 10

Dependencies

# Mandatory:
atomicwrites >=1.2.0           :  1.4.0 (OK)
chardet >=2.0.0                :  4.0.0 (OK)
cloudpickle >=0.5.0            :  1.6.0 (OK)
diff_match_patch >=20181111    :  20200713 (OK)
intervaltree                   :  None (OK)
IPython >=4.0                  :  7.22.0 (OK)
jedi =0.17.1                   :  0.17.1 (OK)
nbconvert >=4.0                :  6.0.7 (OK)
numpydoc >=0.6.0               :  1.1.0 (OK)
paramiko >=2.4.0               :  2.7.2 (OK)
parso =0.7.0                   :  0.7.0 (OK)
pexpect >=4.4.0                :  4.8.0 (OK)
pickleshare >=0.4              :  0.7.5 (OK)
psutil >=5.3                   :  5.8.0 (OK)
pygments >=2.0                 :  2.8.1 (OK)
pylint >=1.0                   :  2.7.4 (OK)
pyls >=0.34.0;<1.0.0           :  0.34.1 (OK)
qdarkstyle >=2.8               :  3.0.2 (OK)
qtawesome >=0.5.7              :  1.0.2 (OK)
qtconsole >=4.6.0              :  5.0.3 (OK)
qtpy >=1.5.0                   :  1.9.0 (OK)
rtree >=0.8.3                  :  0.9.7 (OK)
sphinx >=0.6.6                 :  3.1.2 (OK)
spyder_kernels >=1.9.4;<1.10.0 :  1.9.4 (OK)
watchdog                       :  None (OK)
zmq >=17                       :  20.0.0 (OK)

# Optional:
cython >=0.21                  :  0.29.23 (OK)
matplotlib >=2.0.0             :  3.3.4 (OK)
numpy >=1.7                    :  1.20.1 (OK)
pandas >=0.13.1                :  1.2.4 (OK)
scipy >=0.17.0                 :  1.6.2 (OK)
sympy >=0.7.3                  :  1.8 (OK)

[steff456]

Hi @madphysicist,

Thanks for reporting, I was able to reproduce this issue. @impact27, do you know why this is happening?

[madphysicist]

@steff456 Thanks for confirming. I always have a lingering doubt that I missed something stupid in the docs or configuration when I post bug reports.

[impact27]

It looks like the breakpoints are broken for unsaved files. Can you reproduced for a saved file?

[madphysicist]

@impact27 the file was saved in this example. I used the name untitled0.py out of laziness, but it was on disk in my documents folder as indicated in the output.

I initially started posting the issue because the file wouldn't debug after I modified the function, saved, and reran the cell. But it quickly became apparent that there was no need to do all that. The debugging inline magic breaks even with a completely intact source.

[impact27]

I can't reproduce with the latest 5.x

[impact27]

To solve this for unsaved files, we could remove the last two lines of https://github.com/spyder-ide/spyder-kernels/blob/master/spyder_kernels/customize/namespace_manager.py , but that would mean the files stay cached forever

[madphysicist]

@ccordoba12 Thank you!

[ccordoba12]

@impact27 was the one who really fixed this.

[madphysicist]

@impact27 thank you for the fix. I look forward to using it