What's really frustrating is that this isn't a new idea at all. RPMs have had BuildRequires forever, debs have had a similar concept for a similarly long time.

What's really frustrating is that this isn't a new idea at all. RPMs have had BuildRequires forever, debs have had a similar concept for a similarly long time. Sure, multistage builds are useful, but you could always get the same features (and more) by making packages for whatever distribution you use and installing it in your container. I get that's it's not as easy as writing a shell script in your Dockerfile to build all your dependencies, but sometimes better solutions aren't free. (Also this is one of the reasons why the layer model of deduplication is flawed, and why I'm working on improving it. You shouldn't have to care how large your logical image size is.)