I found some problems in generated js client for rest api and fix it. But code was failed in travis ci (only last simple commit) with error: core.exception.AssertError@source/vibe/core/core.d(1287): Joining tasks in different threads is not yet supported.

I don't touch vibe.core.core.d. Can my changes be a problem of building? Build fails only for dmd-2.068.2 and ldc-1.0.0