如何编写结合其他nix-shell环境的shell.nix文件?

时间:2019-01-20 16:08:45

标签: haskell nix nixpkgs

我想编写一个shell.nix文件,它将为我提供一个包含开发人员工具+ haskell依赖项的开发环境。我想将我的nix表达式分开-现在,这意味着一个文件包含有关我的编辑器的信息,另一个文件包含有关我的haskell项目的信息。

我试图建立一个真正的基本环境,但无法使其正常工作。我有两个文件可以从中创建一个nix-shell

# my-haskell-shell.nix - generated by cabal2nix --shell

{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:

let

  inherit (nixpkgs) pkgs;

  f = { mkDerivation, base, cabal-install, hpack, stdenv }:
      mkDerivation {
        pname = "hello-world";
        version = "0.1.0.0";
        src = ./.;
        isLibrary = false;
        isExecutable = true;
        libraryToolDepends = [ hpack ];
        executableHaskellDepends = [ base ];
        executableToolDepends = [ cabal-install hpack ];
        preConfigure = "hpack";
        license = stdenv.lib.licenses.mit;
      };

  haskellPackages = if compiler == "default"
                       then pkgs.haskellPackages
                       else pkgs.haskell.packages.${compiler};

  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;

  drv = variant (haskellPackages.callPackage f {});

in
  if pkgs.lib.inNixShell then drv.env else drv
# my-neovim-shell.nix

with import <nixpkgs> {};

let
  my-neovim = neovim.override { vimAlias = false; };

in
stdenv.mkDerivation {
  name = "neovim-dev-env";
  buildInputs = [
    my-neovim
  ];
}

这两者都会产生有用的外壳环境! (也就是说,nix-shell my-haskell-env.nixnix-shell my-neovim-env.nix分别给了我cabal和neovim,但不能同时给我)。

我尝试制作一个shell.nix来为两者 neovim和阴谋提供环境的尝试是这样的:

# shell.nix
with import <nixpkgs> {};
let
  my-neovim-shell-env = import ./my-neovim-shell.nix;
  my-haskell-shell-env = import ./my-haskell-shell.nix {};
in
stdenv.mkDerivation {
  name = "my-new-env";
  buildInputs = [
    my-neovim-shell-env
    my-haskell-shell-env
  ];
}

但是,这不起作用。似乎试图建立neovim环境:

 $ nix-shell
these derivations will be built:
  /nix/store/k9ygid1wl75vf2nq7jzfh32mv5f8i956-neovim-dev-env.drv
building '/nix/store/k9ygid1wl75vf2nq7jzfh32mv5f8i956-neovim-dev-env.drv'...
unpacking sources
variable $src or $srcs should point to the source
builder for '/nix/store/k9ygid1wl75vf2nq7jzfh32mv5f8i956-neovim-dev-env.drv' failed with exit code 1
error: build of '/nix/store/k9ygid1wl75vf2nq7jzfh32mv5f8i956-neovim-dev-env.drv' failed

我不知道该如何解决;我究竟做错了什么?我怀疑也许我不应该使用mkDerivation?

1 个答案:

答案 0 :(得分:1)

设法找到解决方案。也许有更好的方法,但这可行:

假设您有一个package.yaml,然后

 $ cabal2nix . > app.nix
# shell.nix
let
  p = import <nixpkgs> {};
  app = p.haskellPackages.callPackage (./app.nix) {};
  lib = p.haskell.lib;
in
lib.overrideCabal app (old: { buildTools = [p.my-nvim] ++ (old.buildTools or []); })

(我在my-nvim上添加了~/.config/nixpkgs/overlays/的地方)

现在我可以访问my-nvim软件包 ghc,等等:

$ nix-shell

$ nvim # works
$ ghc # works

来自https://github.com/p-implies-q/nix-util的灵感