Nixpkgs Flake Input
Q: How should I choose the nixpkgs
input for my flake when using clan-core
?
A: Pin your flake to a recent nixpkgs
version. Here are two common approaches, each with its trade-offs:
Option 1: Follow clan-core
- Pros:
- Recommended for most users.
- Verified by our CI and widely used by others.
- Cons:
- Coupled to version bumps in
clan-core
. - Upstream features and packages may take longer to land.
- Coupled to version bumps in
Example:
inputs = {
clan-core.url = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
# Use the `nixpkgs` version locked in `clan-core`
nixpkgs.follows = "clan-core/nixpkgs";
};
Option 2: Use Your Own nixpkgs
Version
- Pros:
- Faster access to new upstream features and packages.
- Cons:
- Recommended for advanced users.
- Not covered by our CI — you’re on the frontier.
Example:
inputs = {
# Specify your own `nixpkgs` version
nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
clan-core.url = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
# Ensure `clan-core` uses your `nixpkgs` version
clan-core.inputs.nixpkgs.follows = "nixpkgs";
};
Recommended: Avoid Duplicate nixpkgs
Entries
To prevent ambiguity or compatibility issues, check your flake.lock
for duplicate nixpkgs
entries. Duplicate entries indicate a missing follows
directive in one of your flake inputs.
Example of duplicate entries in flake.lock
:
"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"
}
}
To locate the source of duplicate entries, grep your flake.lock
file. For example, if home-manager
is referencing nixpkgs_2
instead of the main nixpkgs
:
Fix this by adding the following line to your flake.nix
inputs:
Repeat this process until all duplicate nixpkgs
entries are resolved. This ensures all inputs use the same nixpkgs
source, preventing cross-version conflicts.