----------------------------- Captured stderr call -----------------------------INFO:traitlets:Executing notebook with kernel: python3INFO:traitlets:Executing notebook with kernel: python3INFO:bookbook.latex:Combined 2 filesINFO:bookbook.latex:Converting to pdf=========================== short test summary info ============================FAILED tests/test_nbcourse.py::test_nbcourse_build - assert 2 == 0======================== 1 failed, 20 passed in 26.34s =========================ERROR: Job failed: exit code 1