My point was just that Docker doesn't ensure reproducibility. Whether a build is reproducible or not depends on the steps used, so its possible but not "ensured".

If you wanted to guarantee reproducibility, a hypothetical purely-functional build system could do that. I personally don't think that's necessary though, or that it would be worth the requisite trade-offs.

Yes, but previous commenter said

> I [thought] Dockerfile ensured that builds are indeed reproducible?

The example straightforwardly disproves that.