2.9 KiB
Q: How should I choose the nixpkgs input for my flake when using clan-core?
A: In general, you should pin your flake to a recent nixpkgs version. There are two common ways to do this, each with its own trade-offs:
Follow clan-core
- (+) Recommended for most people.
- (+) Verified by our CI and widely used by others
- (-) Coupling to version bumps in clan-core,
- Upstream features and packages may take longer to land.
inputs = {
clan-core.url = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
# Uses the nixpkgs version that was locked in clan-core
nixpkgs.follows = "clan-core/nixpkgs";
}
Use your own nixpkgs version
- (+) Faster access to new upstream features and packages
- (-) Recommended for advanced usage.
- (-) Not covered by our CI — you’re on the frontier
inputs = {
# Use your own version here.
nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
clan-core.url = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
# Uses the nixpkgs version of your own flake in clan-core
clan-core.inputs.nixpkgs.follows = "nixpkgs";
}
Recommended
To avoid ambiguity or incompatibility issues, it’s a good idea to check your flake.lock for duplicate nixpkgs entries.
This usually indicates that one of your flake inputs is missing a follows directive.
If you see something like this, it means you have multiple versions of nixpkgs:
"nixpkgs": {
"locked": {
"lastModified": 315532800,
"narHash": "sha256-1tUpklZsKzMGI3gjo/dWD+hS8cf+5Jji8TF5Cfz7i3I=",
"rev": "08b8f92ac6354983f5382124fef6006cade4a1c1",
"type": "tarball",
"url": "https://releases.nixos.org/nixpkgs/nixpkgs-25.11pre862603.08b8f92ac635/nixexprs.tar.xz"
},
"original": {
"type": "tarball",
"url": "https://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz"
}
},
"nixpkgs_2": {
"locked": {
"lastModified": 1758346548,
"narHash": "sha256-afXE7AJ7MY6wY1pg/Y6UPHNYPy5GtUKeBkrZZ/gC71E=",
"owner": "nixos",
"repo": "nixpkgs",
"rev": "b2a3852bd078e68dd2b3dfa8c00c67af1f0a7d20",
"type": "github"
},
"original": {
"owner": "nixos",
"ref": "nixos-25.05",
"repo": "nixpkgs",
"type": "github"
}
},
You can grep through your lock file to locate which inputs are referencing the wrong nixpkgs.
In this example, home-manager is pointing to nixpkgs_2 instead of the main nixpkgs
// ...
"home-manager": {
"inputs": {
"nixpkgs": "nixpkgs_2"
}
// ...
To fix this add the following line to your flake.nix inputs:
home-manager.inputs.nixpkgs.follows = "nixpkgs";
Repeat this process until all duplicate nixpkgs entries are eliminated.
This helps prevent cross-version conflicts and ensures all inputs use the same nixpkgs source.