init reproducibilty

npins/default.nix

@@ -0,0 +1,47 @@
+# Generated by npins. Do not modify; will be overwritten regularly
+let
+  data = builtins.fromJSON (builtins.readFile ./sources.json);
+  version = data.version;
+
+  mkSource = spec:
+    assert spec ? type; let
+      path =
+        if spec.type == "Git" then mkGitSource spec
+        else if spec.type == "GitRelease" then mkGitSource spec
+        else if spec.type == "PyPi" then mkPyPiSource spec
+        else if spec.type == "Channel" then mkChannelSource spec
+        else builtins.throw "Unknown source type ${spec.type}";
+    in
+    spec // { outPath = path; };
+
+  mkGitSource = { repository, revision, url ? null, hash, ... }:
+    assert repository ? type;
+    # At the moment, either it is a plain git repository (which has an url), or it is a GitHub/GitLab repository
+    # In the latter case, there we will always be an url to the tarball
+    if url != null then
+      (builtins.fetchTarball {
+        inherit url;
+        sha256 = hash; # FIXME: check nix version & use SRI hashes
+      })
+    else assert repository.type == "Git"; builtins.fetchGit {
+      url = repository.url;
+      rev = revision;
+      # hash = hash;
+    };
+
+  mkPyPiSource = { url, hash, ... }:
+    builtins.fetchurl {
+      inherit url;
+      sha256 = hash;
+    };
+
+  mkChannelSource = { url, hash, ... }:
+    builtins.fetchTarball {
+      inherit url;
+      sha256 = hash;
+    };
+in
+if version == 3 then
+  builtins.mapAttrs (_: mkSource) data.pins
+else
+  throw "Unsupported format version ${toString version} in sources.json. Try running `npins upgrade`"

npins/sources.json

@@ -0,0 +1,24 @@
+{
+  "pins": {
+    "krops": {
+      "type": "GitRelease",
+      "repository": {
+        "type": "Git",
+        "url": "https://cgit.krebsco.de/krops"
+      },
+      "pre_releases": false,
+      "version_upper_bound": null,
+      "version": "1.28.2",
+      "revision": "59aa5d0e41cf4a6d4356673feb1adbd0fcf68936",
+      "url": null,
+      "hash": "1a2pgg52y577lpvg2kcyblr2lgjij1l2d4vv1i8xd5gmsaphcfji"
+    },
+    "nixpkgs": {
+      "type": "Channel",
+      "name": "nixpkgs-unstable",
+      "url": "https://releases.nixos.org/nixpkgs/nixpkgs-23.05pre483213.635a306fc8e/nixexprs.tar.xz",
+      "hash": "0lvmz0l12qkyg7lj69mn03lv8i44xsw84ld4d8yqyj9m9dng7hsd"
+    }
+  },
+  "version": 3
+}

shell.nix

@@ -0,0 +1,6 @@
+{ pkgs ? import (import ./npins { }).nixpkgs {} }:
+pkgs.mkShell {
+  packages = [
+    pkgs.npins
+  ];
+}