reproducible images are one of those features where the payoff is mostly emotional until the day it isn't. we had an incident where two supposedly identical images on two machines had a three byte delta in a timestamp and it cost us an afternoon to bisect from the wrong end. boring win, but a real one.

This is a really interesting accomplishment - I am also working heavily on reproducible builds for my firmware projects, and .. lo and behold .. the package manager key administrivia is the final bone to be broken.

I wonder if Arch leading the way on this will prompt other distro's to attempt the same feat. Reproducible builds are important for certification, security and safety-critical applications .. it'd be great to see Linux distros become more conformant to this method.

All docker containers should have been like that. apt-get update in a docker build step is an anti pattern.

and they said compilers are deterministic...

This is a huge accomplishment! But it wouldn't be so huge if compilers were trivially deterministic. It took 5 decades of development for compilers to get here. I'm sure ChatGPT in 2073 is going to be more deterministic than it was in 2023.