On Sep 4, 2018, at 6:06 AM, Alex Walters <tritium-list@sdamon.com> wrote:

Since zlib is a dependency of python, the assumption has to be that it is
already present.

It is technically an optional dependency of Python, though I don’t think you can install wheels without zlib present since wheels are zip files and generally include compression. Although maybe it could work in niche scenarios if someone built wheels using ZIP_STORED instead of ZIP_DEFLATE?