[MD87]

Docker images actually contain the timestamp each layer was built at, so are basically de-facto non-reproducible.

Buildah from Red Hat has an argument to set this programmatically instead of using the current date, but AFAIK there's no way to do that with plain old docker build.

[gmfawcett]

The nixpkgs workaround is to build images with build-date == 1970-01-01. Annoying but reproducible.