The renaming of compiled c test modules in #10790 broke the scikit-learn tests because we were using numpy.core.umath_tests.inner1d. There was no good reason to use inner1d and we now used standard numpy constructs in scikit-learn master. The problem is that it will affect the latest scikit-learn (0.19.1) as soon as numpy 1.15 is released. Given the current rate of release, it is rather likely that numpy 1.15 will be released before the next scikit-learn release (0.20).

It feels like other projects could be using some of the renamed modules, so maybe the safest approach would be to keep the old modules around for a deprecation cycle with a DeprecationWarning saying that this modules are for numpy internal use only. Would you be willing to consider this option?

I first commented in #10790 (comment) but @charris suggested I opened a new issue, so here it is!