failed to run unit test

[quesnel]

$ ctest -VV
Test project /home/goth/git/vle/pyvle/build
Constructing a list of tests
Done constructing a list of tests
Checking test dependency graph...
Checking test dependency graph end
test 1
Start 1: test_python

1: Test command: /home/goth/git/vle/pyvle/tests/pyvletest.py "/home/goth/git/vle/pyvle/tests"
1: Test timeout computed to be: 9.99988e+06
1: .I/O warning : failed to load external entity "exp/not_existing_file"
1: I/O warning : failed to load external entity "exp/not_existing_file"
1: .Entity: line 1: parser error : Start tag expected, '<' not found
1: not a valid vpz
1: ^
1: ...........I/O warning : failed to load external entity "exp/tmp/tmpRgRnl9"
1: I/O warning : failed to load external entity "exp/tmp/tmpRgRnl9"
1: F.................
1: ======================================================================
1: FAIL: testSaveInFilename (pyvle_experiment.TestExperiment)
1: ----------------------------------------------------------------------
1: Traceback (most recent call last):
1: File "/home/goth/git/vle/pyvle/tests/pyvle_experiment.py", line 71, in testSaveInFilename
1: self.assertIsInstance(exp_test.vpz, libpyvle.Vpz)
1: AssertionError: None is not an instance of <class 'libpyvle.Vpz'>
1:
1: ----------------------------------------------------------------------
1: Ran 31 tests in 0.083s
1:
1: FAILED (failures=1)
1/1 Test #1: test_python ...................... Passed 1.24 sec

100% tests passed, 0 tests failed out of 1