nixpkgsupd

Updates Nix flakes found in Nix's garbage collector roots and provides tools to manage the garbage collector roots.

This is most useful for nixos-unstable users to reduce Nix store size because packages update often.

Usage

$ nixpkgsupd --target ~/.nixos-config'#'nixpkgs list
nixpkgs target: nixos-unstable last updated a month ago
/home/axel/dev/example (direnv): nixos-25.05 1f08a4df998e21f4e8be8fb6fbf61d11a1a5076a last updated 3 days ago

$ nixpkgsupd --target ~/.nixos-config'#'nixpkgs update
Note: This is a dry run. To modify files and run commands, run again with --allow-write
nixpkgs target: nixos-unstable last updated a month ago

/home/axel/dev/example (direnv): nixos-25.05 1f08a4df998e21f4e8be8fb6fbf61d11a1a5076a last updated 3 days ago
 {
   description = "A basic flake with a shell";
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
   inputs.flake-utils.url = "github:numtide/flake-utils";

   outputs = { nixpkgs, flake-utils, ... }:
(1/6) [a,n,e,sh,up,dg,lock,direnv,commit,?]

Development

0. Have Linux or MacOS

1. Install Nix

2. Run the command nix develop in a shell.

   This creates a bash subshell with all the dependencies.

3. Run cargo commands as you like.

   i.e. cargo build, cargo run, cargo clippy, etc.

Contributing patches

Please first make sure that you have not introduced any regressions and format the code by running the following commands at the repository root.

cargo fmt
cargo clippy
cargo test

Make a GitHub pull request.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.