Little regression after passing to python 3.7.3:
less than 1 : 36
less than 2 : 56
less than 4 : 84
less than 8 : 94
less than 16 : 102
less than 64 : 105
In the 15 worst files, 178 broken doctests:
['src/sage/groups/perm_gps/permgroup.py # 7 doctests failed',
'src/sage/graphs/generic_graph.py # 8 doctests failed',
'src/sage/libs/ntl/ntl_ZZ_pX.pyx # 8 doctests failed',
'src/sage/numerical/backends/cvxopt_backend.pyx # 8 doctests failed',
'src/sage/doctest/sources.py # 9 doctests failed',
'src/sage/misc/nested_class.pyx # 9 doctests failed',
'src/sage/numerical/sdp.pyx # 9 doctests failed',
'src/sage/rings/integer.pyx # 9 doctests failed',
'src/sage/symbolic/expression.pyx # 9 doctests failed',
'src/sage/symbolic/constants.py # 12 doctests failed',
'src/sage/combinat/cluster_algebra_quiver/cluster_seed.py # 13 doctests failed',
'src/sage/combinat/cluster_algebra_quiver/quiver.py # 14 doctests failed',
'src/sage/misc/classcall_metaclass.pyx # 20 doctests failed',
'src/sage/matroids/matroid.pyx # 21 doctests failed',
'src/sage/combinat/finite_state_machine.py # 22 doctests failed']