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File "src/sage/numerical/backends/coin_backend.pyx", line 39, in sage.numerical.backends.coin_backend.CoinBackend
Failed example:
    TestSuite(p).run(skip="_test_pickling")               # optional - cbc
Expected nothing
Got:
    Failure in _test_solve:
    Traceback (most recent call last):
      File "/home/jdemeyer/sage-git/local/lib/python2.7/site-packages/sage/misc/sage_unittest.py", line 283, in run
        test_method(tester = tester)
      File "sage/numerical/backends/generic_backend.pyx", line 697, in sage.numerical.backends.generic_backend.GenericBackend._test_solve (build/cythonized/sage/numerical/backends/generic_backend.c:8748)
        with tester.assertRaises(MIPSolverException) as cm:   # unbounded
      File "/home/jdemeyer/sage-git/local/lib/python/unittest/case.py", line 116, in __exit__
        "{0} not raised".format(exc_name))
    AssertionError: MIPSolverException not raised
    ------------------------------------------------------------
    The following tests failed: _test_solve
**********************************************************************

sage: from sage.numerical.backends.coin_backend import CoinBackend
sage: p = CoinBackend()
sage: p.add_linear_constraints(5, 0, None)
sage: p.add_col(range(5), range(5))
sage: p.objective_coefficient(0,1)
sage: p.solve()
0
sage: p.set_verbosity(3)
sage: p.solve()
Cbc3007W No integer variables - nothing to do
Clp0006I 0  Obj 0 Dual inf 0.9999999 (1)
Clp0000I Optimal - objective value -1.7976931e+308
0   ### Instead, an exception should have been raised.
sage: p.get_variable_value(0)
1.7976931348623157e+308  ### BAD