Serializing issue on Windows when gcov_tool specified to twister at the command line

[solsbarry]

Describe the bug
I have a on target unit test that I am executing with twister and asking it to generate a code coverage report for. The build failed with this error:

Here is a copy of the report being passed to json.dump

The issue is that I am specifying a gcov_tool at the command line call to twister
twister....--coverage --gcov-tool my_windows_path...
And as you can see somehow twister is turning the gcov_tool path into a WindowsPath variable and not a string. And apparently a Windows Path type can't be in a dictionary passed to json.dump. That is the issue.

In reports.py I updated jason_report() to convert WindowsPath types in the report to strings, and that caused it to build fine. I am not suggesting that is the best answer, but something like it.

You also have to add this at the top to get it to build
from pathlib import WindowsPath
Here is the text of that code if you want to try it.

def convert_windows_paths_to_strings(self, d):
      if isinstance(d, dict):
          return {k: self.convert_windows_paths_to_strings(v) for k, v in d.items()}
      elif isinstance(d, list):
          return [self.convert_windows_paths_to_strings(i) for i in d]
      elif isinstance(d, WindowsPath):
          return str(d)
      else:
          return d

To Reproduce
Steps to reproduce the behavior:

1. Create a unit test
2. Run it on Windows with twister, while specifying the path to gcov_tool in the twister command and enabling coverage.
   twister....--coverage --gcov-tool my_windows_path...
3. See error

Expected behavior
The unit test should build without error

Impact
Can't include coverage in my on target unit tests when running on windows.

Environment (please complete the following information):

• OS: Windows 10
• Toolchain: Zephyr SDK 0.16.8
• Commit SHA or Version used: 3.7.88-NCS1 ( I know that is a nordic version, but I think this issue is specific to Zephyr more generally.

[nashif]

@golowanow here

zephyr/scripts/pylib/twister/twisterlib/reports.py

Line 297 in ebbdb10

# Resolve known JSON serialization problems.

you already deal with PosixPath, need to make this also work with WindowsPath.

[golowanow]

@solsbarry, could you please check #84334 at your environment ?

[solsbarry]

@golowanow That fixed the issue. Thank you very much, I appreciate the quick fix.