Dependency management for random third-party codebases I have happened to want to build from source.

Say I find a bug in some open source project and I feel motivated to fix it. A recent example of this was when I found a UI bug in this excellent LLM visualizer.

The first step is to build that project locally, from source. Thankfully, this repo has pretty simple instructions to get started:

1. Install dependencies: `yarn`
2. Start the dev server: `yarn dev`

So I make a little flake that just installs yarn, and I run yarn and yarn dev as instructed. Good stuff.

Then I get a little deeper into the project and find that fixing the bug requires editing one of the .odin files in the repo. This isn't mentioned in the getting started instructions, but rebuilding the odin files requires having an odin compiler installed and running the relevant build.sh script. And unfortunately, the latest odin compiler won't work: odin's syntax has changed in a backward-incompatible way since this code was written. So I go hunting for a compatible version. Eventually I binary-search my way to odin version dev-2023-05. Cool. This version was added to the public nixpkgs repo in https://github.com/NixOS/nixpkgs/commit/38e5815. I add that to my flake and now I have the compiler.

I successfully compile the old odin code and I'm back on my way to fixing the bug.

Using this flake, I've created a development environment that lets me work on this project. I've done it in a way that I can easily recreate elsewhere if needed, and I've done it without making global changes to my system. I find this really helpful, and having this available makes me feel more empowered to work on any arbitrary codebase I stumble on.