Unable to generate backend coverage report

[lkbhitesh07]

Describe the bug
When I try to locally generate the backend coverage check, I'm not able to get the results. The script ends with this error Can't combine line data with arc data.

To Reproduce
Steps to reproduce the behavior:

1. Run any backend test with the flag --generate_coverage_report
2. See the error

Observed behavior
Receiving the error instead of a coverage report.

Expected behavior
I should be able to see the coverage report.

Screenshots / Videos

Desktop (please complete the following information; delete this section if the issue does not arise on desktop):

• OS: Ubuntu
• Browser: Chrome
• Browser-version: [e.g. 22]

[lkbhitesh07]

Hey @IamEzio @U8NWXD, WIll you please take a look at this? I'm kind of blocked on this particular part.
Thanks

[IamEzio]

Hi @lkbhitesh07, I too am investigating this issue for a while now. But normally it means that the coverage for the target file is 100% and you can go ahead.

[lkbhitesh07]

Hi @lkbhitesh07, I too am investigating this issue for a while now. But normally it means that the coverage for the target file is 100% and you can go ahead.

Oh! but that is not the case here. I do have some coverage left but I'm not able to see it.
Edit Also can you please tell me a temporary hack to disable the branch coverage?

[U8NWXD]

@lkbhitesh07 can you try deleting any .coverage.* data files? See https://stackoverflow.com/a/56478984

[U8NWXD]

Other possibly useful links:

• Internal error "Can't combine line data with arc data" for code using subprocesses pytest-dev/pytest-cov#243
• pytest and multiprocessing: CoverageException: Can't combine line data with arc dat nedbat/coveragepy#512

[lkbhitesh07]

Thanks, @U8NWXD

[lkbhitesh07]

Hey @U8NWXD, Just wanted to report this one thing. After removing the coverage files as suggested, the previous error was gone but I was introduced to this new error:

Ran 12 tests in 1 test class.
All tests passed.
Combined data file .coverage.lkbhitesh07-HP-Laptop-15-da0077tx.184650.blpaorkmiazuvusa
Traceback (most recent call last):
  File "/home/lkbhitesh07/.pyenv/versions/3.7.10/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/home/lkbhitesh07/.pyenv/versions/3.7.10/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/lkbhitesh07/Desktop/oppia/oppia/scripts/run_backend_tests.py", line 609, in <module>
    main()
  File "/home/lkbhitesh07/Desktop/oppia/oppia/scripts/run_backend_tests.py", line 536, in main
    report_stdout, coverage = check_coverage(True)
  File "/home/lkbhitesh07/Desktop/oppia/oppia/scripts/run_backend_tests.py", line 603, in check_coverage
    coverage = float(coverage_result.group('total'))
AttributeError: 'NoneType' object has no attribute 'group'

I tried going through the links you provided but I wasn't able to get much info as I'm not much familiar with the internal concepts of coverage part.
Thanks

[U8NWXD]

Are there any errors farther up? This message usually means that the coverage report was malformed

[U8NWXD]

Closing due to inactivity. @lkbhitesh07 please feel free to reopen if you're still having issues