First, be sure that you:
The primary way to get help is through the khmer discussion list: http://lists.idyll.org/listinfo/khmer, though we are also available for closer-to-realtime support via Gitter.
uname -mrs
python --version
pip freeze | grep khmer
You are also welcome to report an issue you are having using GitHub: https://github.com/dib-lab/khmer/issues/new