[Python-modules-team] Bug#911688: willow FTBFS: ModuleNotFoundError: No module named 'cv2'

[Helmut Grohne]

Source: willow
Version: 1.1-3
Severity: serious
Tags: ftbfs

willow fails to build from source in unstable for multiple
architectures, e.g. amd64:

https://tests.reproducible-builds.org/debian/rbuild/unstable/amd64/willow_1.1-3.rbuild.log.gz

| ======================================================================
| ERROR: test_has_animation (tests.test_opencv.TestOpenCVOperations)
| ----------------------------------------------------------------------
| Traceback (most recent call last):
|   File "/build/1st/willow-1.1/.pybuild/cpython3_3.7_willow/build/willow/plugins/opencv.py", line 10, in _cv2
|     import cv2
| ModuleNotFoundError: No module named 'cv2'
| 
| During handling of the above exception, another exception occurred:
| 
| Traceback (most recent call last):
|   File "/build/1st/willow-1.1/.pybuild/cpython3_3.7_willow/build/tests/test_opencv.py", line 16, in setUp
|     colour_image = OpenCVColorImage.from_buffer_rgb(buffer_rgb)
|   File "/build/1st/willow-1.1/.pybuild/cpython3_3.7_willow/build/willow/plugins/opencv.py", line 58, in from_buffer_rgb
|     cv2 = _cv2()
|   File "/build/1st/willow-1.1/.pybuild/cpython3_3.7_willow/build/willow/plugins/opencv.py", line 12, in _cv2
|     from cv import cv2
| ModuleNotFoundError: No module named 'cv'
| 
| ----------------------------------------------------------------------
| Ran 96 tests in 2.393s
| 
| FAILED (errors=5, expected failures=7)
| E: pybuild pybuild:338: test: plugin distutils failed with: exit code=1: cd /build/1st/willow-1.1/.pybuild/cpython3_3.7_willow/build; python3.7 -m unittest discover -v
| dh_auto_test: pybuild --test -i python{version} -p "3.7 3.6" returned exit code 13
| make: *** [debian/rules:6: build] Error 25
| dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2

Helmut