@@ -1,25 +1,17 @@
11# Haskell.nix Nixpkgs Pin
22
3−Haskell.nix contains a Nixpkgs pin in
4−[`nixpkgs/github.json`](https://github.com/input-output-hk/haskell.nix/blob/master/nixpkgs/github.json).
5−This is the version of Nixpkgs used for builds of `nix-tools` and
6−running the tests.
3+Haskell.nix contains several Nixpkgs pins imanaged by `niv` in
4+`nix/sources.json`.
5+
6+These are used in testing various versions of nixpkgs.
77
88To use haskell.nix the `config` and `overlays` need to be applied to
99Nixpkgs. Users should probably pin a suitable version of nixpkgs, although things might not work for them if their Nixpkgs version is
1010too different.
1111
1212We aim to keep this pin somewhere on a channel of the **Nixpkgs latest
13−stable release**. That is currently 19.09.
13+stable release**. That is currently 20.09.
1414
1515We also execute tests on MacOS (darwin). The darwin channel is usually
16−behind the NixOS channel. So we choose the `nixpkgs-19.09-darwin`
17−channel:
18−
19−```
20−nix-prefetch-git https://github.com/NixOS/nixpkgs-channels refs/heads/nixpkgs-19.09-darwin
21−```
22−
23−Keep the URL in `github.json` pointing at
24−<https://github.com/NixOS/nixpkgs>. Case matters because the Hydra
25−trusted URL whitelist is case-sensitive.
16+behind the NixOS channel. So we follow the `nixpkgs-20.09-darwin`
17+channel.