At work we are issued a very fast Apple MacBook Pro (mine is an M4 with 64GB RAM) and we take that fast machine and install Microsoft Defender on it, which takes that fast computer and makes it wade through a swamp. This post isn’t about the pain that I go through daily to try to develop directly on my Mac (that should be a separate series of posts) but today I want to talk about how I have greatly improved my nix-darwin switch speeds.

FreshRSS has been my RSS feed aggregator of choice for a couple of years now. I still frequently long for the optimistic heady days when we all loved Google Reader. I used Feedbin for many years and highly recommend it if self-hosting your feed aggregator isn’t for you. Lovely service for sure.

Background

Ever since I set up FreshRSS I’ve been grumbling about how I want SSO. I use Authentik for most of my SSO needs, but these days even that feels overkill. You can use Authentik with FreshRSS but only if you use the FreshRSS Docker container (which has Apache inside of it to do the authentication). This feels extra-heavy for me when FreshRSS is “just” a PHP app.

Nix is a tool that creates immutable derivations of configurations written in a functional language. This means we don’t depend on our system’s environment at run or build time to create a package, instead we declare all of the dependencies and build in an isolated environment to avoid pollution (a pure environment in nix terms). Because we have declared all of our dependencies, it also means that we can re-build the same exact package again and again (and again!) without worrying about whether we remembered to install libssl-dev before starting to compile or if the new version of a library will break our software because the maintainer make a breaking change in a patch dependency. Plus we can try software out and quickly discard it without worrying about all the extra packages it required.