sage -tp src/sage/graphs/generic_graph.py src/sage/graphs/graph.py

Using --optional=4ti2,build,ccache,cryptominisat,dochtml,dot2tex,e_antic,fricas,glucose,latte_int,libnauty,lidia,lrslib,memlimit,normaliz,notedown,openssl,pandoc_attributes,pycosat,pynormaliz,rst2ipynb,sage,sage_numerical_backends_coin

sage -t --random-seed=0 src/sage/graphs/graph.py
**********************************************************************
File "src/sage/graphs/graph.py", line 4507, in sage.graphs.graph.Graph.has_homomorphism_to
Failed example:
    g.has_homomorphism_to(graphs.CycleGraph(4)) is not False
Expected:
    False
Got:
    True
**********************************************************************
File "src/sage/graphs/graph.py", line 4902, in sage.graphs.graph.Graph.minor
Failed example:
    L = g.minor(graphs.CompleteGraph(3))
Expected:
    Traceback (most recent call last):
    ...
    ValueError: This graph has no minor isomorphic to H !
Got:
    <BLANKLINE>
**********************************************************************
File "src/sage/graphs/graph.py", line 6112, in sage.graphs.graph.Graph.topological_minor
Failed example:
    g.topological_minor(graphs.CycleGraph(3))
Expected:
    False
Got:
    Subgraph of (Subgraph of (RandomGNP(15,0.300000000000000))): Graph on 0 vertices
**********************************************************************
3 items had failures:
   1 of  10 in sage.graphs.graph.Graph.has_homomorphism_to
   1 of  12 in sage.graphs.graph.Graph.minor
   1 of   7 in sage.graphs.graph.Graph.topological_minor
    [1229 tests, 3 failures, 12.35 s]
sage -t --random-seed=0 src/sage/graphs/generic_graph.py
**********************************************************************
File "src/sage/graphs/generic_graph.py", line 8909, in sage.graphs.generic_graph.GenericGraph.nowhere_zero_flow
Failed example:
    h = g.nowhere_zero_flow(k=3)
Expected:
    Traceback (most recent call last):
    ...
    EmptySetError: the problem has no feasible solution
Got:
    <BLANKLINE>
**********************************************************************
File "src/sage/graphs/generic_graph.py", line 9530, in sage.graphs.generic_graph.GenericGraph.disjoint_routed_paths
Failed example:
    p1,p2 = g.disjoint_routed_paths([((0, 0), (4, 4)), ((0, 4), (4, 0))])
Expected:
    Traceback (most recent call last):
    ...
    EmptySetError: the disjoint routed paths do not exist
Got:
    <BLANKLINE>
**********************************************************************
2 items had failures:
   1 of   5 in sage.graphs.generic_graph.GenericGraph.disjoint_routed_paths
   1 of  29 in sage.graphs.generic_graph.GenericGraph.nowhere_zero_flow
    [3458 tests, 2 failures, 13.67 s]
----------------------------------------------------------------------
sage -t --random-seed=0 src/sage/graphs/graph.py  # 3 doctests failed
sage -t --random-seed=0 src/sage/graphs/generic_graph.py  # 2 doctests failed
----------------------------------------------------------------------

$ sage -optional | grep coin
sage_numerical_backends_coin............9.0b12 (9.0b12)
$ sage -optional | grep cbc
cbc.....................................2.9.4.p0 (not_installed)
$ cbc --version
Welcome to the CBC MILP Solver 
Version: 2.9.9 
Build Date: Aug 21 2017