I'm wondering if it's possible to combine coverage.xml files into 1 file to see global report in HTML output.
I've got my unit/functional tests running as 1 command and integration tests as the second command. That means my coverage for unit/functional tests are overridden by unit tests.
That would be great if I had some solution for that problem, mainly by combining those files into 1 file.
I had similar case where I had multiple packages and each of them had its tests and they were run using own testrunner. so I could combine all the coverage xml by following these steps.

Indivisually generate the coverage report.
You would need to naviagte to each package and generate the report in that package. This would create .coverage file. You can also add [run]parallel=True in your .coveragerc to create coverage file appended with machine name and processid.

Aggregate all the reports.
You need to copy all the .coverage files to for these packages to a seaparte folder. You might want to run a batch or sh script to copy all the coverage files.

Run combine.
Now naviagte tp the folder when you have all the report files and then run coverage combine. This will delete all the coverage files and combine it to one .coverage file. Now you can run coverage html and coverage xml.
combine python coverage files?