Try this WIP

ci/azure-pipelines-steps.yml

@@ -69,11 +69,9 @@ steps:
 
 - script: |
     tox
-    ls -a .coverage_dir
   displayName: 'tox'
 
 - script: |
-    pwd
-    ls -a
-    codecov --required -t 813fb6da-087d-4b36-a185-5a530cab3455 --file coverage.xml
+    python3 ci/fix_coverage.py
+    codecov --required -t 813fb6da-087d-4b36-a185-5a530cab3455
   displayName: 'codecov'

ci/fix_coverage.py

@@ -0,0 +1,27 @@
+"""
+Helper script to combine coverage (as codecov seems to have problems...).
+Written in python to be cross-plotform
+"""
+
+from os import chdir, listdir
+from pathlib import Path
+from pprint import pprint
+from subprocess import run
+
+THIS_FILE = Path(__file__)
+GIT_MAIN_DIR = THIS_FILE.parent.parent.resolve()
+COVERAGE_DIR = GIT_MAIN_DIR.joinpath('.coverage_dir')
+
+def main():
+    chdir(GIT_MAIN_DIR)
+    print(f"Working in {GIT_MAIN_DIR}, listing coverage dir {COVERAGE_DIR}")
+    pprint(listdir(COVERAGE_DIR))
+    run(['coverage', 'combine'] + COVERAGE_DIR.glob('coverage-*'), check=True)
+    print(f"Combined coverage, listing {GIT_MAIN_DIR}")
+    pprint(listdir(GIT_MAIN_DIR))
+    run(['coverage', 'xml'], check=True)
+    print(f"Created coverage xml, listing {GIT_MAIN_DIR}")
+    pprint(listdir(GIT_MAIN_DIR))
+
+if __name__ == '__main__':
+    main()

tox.ini

@@ -30,13 +30,12 @@ commands =
     test: python -c "import sys; print('64 bit?', sys.maxsize > 2**32)"
     test: python {toxinidir}/ci/fix_paths.py
     test: python -m pytest --pyargs h5py --cov=h5py --cov-config={toxinidir}/.coveragerc {posargs}
-    test: python -m coverage xml -i '{toxinidir}/.coverage_dir/coverage*' -o {toxinidir}/coverage.xml
 changedir =
     test: {toxworkdir}
 passenv =
     HDF5_DIR
 setenv =
-    COVERAGE_FILE={toxinidir}/.coverage_dir/coverage
+    COVERAGE_FILE={toxinidir}/.coverage_dir/coverage-{envname}
 # needed otherwise coverage cannot find the file when reporting
 
 pip_pre =