Nixpkgs build by attribute path script without evaluating entire nixpkgs

build-by-path.sh

#! /usr/bin/env nix-shell
#! nix-shell -i bash -p jq
# Build nixpkgs packages by path without completely evaluating nixpkgs
#
# Usage:
#   build-by-path.sh NIXPKGS_PATH NIX_PATH 'SYSTEM'
#
# Examples:
#   build-by-path.sh . 'vimPlugins' 'aarch64-darwin'
#   build-by-path.sh ~/nixpkgs hello 'x86_64-linux'

set -ex

NIXPKGS_PATH=$(realpath "$1")
ATTR_PATH=$2
SYSTEM=$3

TMP_DIR=$(mktemp -d)

if command -v nom >/dev/null 2>&1; then
  echo "NOM found, using it"
  NIX="nom"
else
  NIX="nix"
fi

echo "(import \"$NIXPKGS_PATH\" { }).$ATTR_PATH" > "$TMP_DIR/to-eval.nix"

nix-env \
  --extra-experimental-features no-url-literals \
  --option system "$SYSTEM" \
  -f "$TMP_DIR/to-eval.nix" \
  -qaP \
  --json \
  --out-path \
  --show-trace \
  --no-allow-import-from-derivation \
  | jq 'keys' \
  > "$TMP_DIR/attrs.json"

# https://github.com/Mic92/nixpkgs-review/blob/907925df227584ae4c0eb38db51fd23fe495d276/nixpkgs_review/nix/evalAttrs.nix
cat >"$TMP_DIR/to-build.nix" << NIX
with builtins;
let
  root-path = "$ATTR_PATH";
  nixpkgs-path = "$NIXPKGS_PATH";
  system = "$SYSTEM";
  attr-json = "$TMP_DIR/attrs.json";

  pkgs = import nixpkgs-path {
    inherit system;
    config = {
      allowBroken = false;
    };
  };
  inherit (pkgs) lib;

  attrs = fromJSON (readFile attr-json);
  getProperties =
    name':
    let
      name = if name' == "" then root-path else name';
      stringAttrPath = if builtins.length attrs > 1 then root-path + "." + name else name;
      attrPath = lib.splitString "." stringAttrPath;
      pkg = lib.attrByPath attrPath null pkgs;
      exists = lib.hasAttrByPath attrPath pkgs;
    in
    if pkg == null then
      {
        inherit name;
        path = pkgs.hello;
      }
    else
      lib.forEach (pkg.outputs or [ "out" ]) (
        output:
        let
          # some packages are set to null if they aren't compatible with a platform or package set
          maybePath = tryEval "\${lib.getOutput output pkg}";
          broken = !exists || !maybePath.success;
        in
        if broken then
          {
            name = name;
            path = pkgs.hello;
          }
        else
          {
            name = (if output == "out" then name else "\${name}.\${output}");
            path = pkg;
          }
      );

  filteredPackages = concatMap getProperties attrs;
in
pkgs.linkFarm "test" filteredPackages
NIX

"$NIX" build \
  --file "$TMP_DIR/to-build.nix" \
  --extra-experimental-features 'nix-command no-url-literals' \
  --no-link \
  --keep-going \
  --show-trace \
  --no-allow-import-from-derivation \
  --nix-path "$NIXPKGS_PATH"

rm -rf "$TMP_DIR"

LICENSE.md

Copyright 2024 Perchun Pak

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.