Abandon flakes in favour of npins

Flakes copy the whole gigantic repo to store all the time, quickly eating all the drive capacity.

npins/default.nix

@@ -0,0 +1,80 @@
+# 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 ${spec.type}";
+    in
+    spec // { outPath = path; };
+
+  mkGitSource =
+    {
+      repository,
+      revision,
+      url ? null,
+      hash,
+      branch ? null,
+      ...
+    }:
+    assert repository ? type;
+    # At the moment, either it is a plain git repository (which has an url), or it is a GitHub/GitLab repository
+    # In the latter case, there we will always be an url to the tarball
+    if url != null then
+      (builtins.fetchTarball {
+        inherit url;
+        sha256 = hash; # FIXME: check nix version & use SRI hashes
+      })
+    else
+      assert repository.type == "Git";
+      let
+        urlToName =
+          url: rev:
+          let
+            matched = builtins.match "^.*/([^/]*)(\\.git)?$" repository.url;
+
+            short = builtins.substring 0 7 rev;
+
+            appendShort = if (builtins.match "[a-f0-9]*" rev) != null then "-${short}" else "";
+          in
+          "${if matched == null then "source" else builtins.head matched}${appendShort}";
+        name = urlToName repository.url revision;
+      in
+      builtins.fetchGit {
+        url = repository.url;
+        rev = revision;
+        inherit name;
+        # 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 +1,29 @@
+{
+  "pins": {
+    "hakyll-contrib-tojnar": {
+      "type": "Git",
+      "repository": {
+        "type": "GitLab",
+        "repo_path": "tojnar.cz/hakyll-contrib-tojnar",
+        "server": "https://gitlab.com/"
+      },
+      "branch": "master",
+      "revision": "v0.2.2",
+      "url": "https://gitlab.com/api/v4/projects/tojnar.cz%2Fhakyll-contrib-tojnar/repository/archive.tar.gz?sha=v0.2.2",
+      "hash": "1s9qjwadl0krzvs77d537pbyvr4mkkmjgdl79kc8lgil4y182v3m"
+    },
+    "nixpkgs": {
+      "type": "Git",
+      "repository": {
+        "type": "GitHub",
+        "owner": "NixOS",
+        "repo": "nixpkgs"
+      },
+      "branch": "nixpkgs-unstable",
+      "revision": "aeb75dba965e790de427b73315d5addf91a54955",
+      "url": "https://github.com/NixOS/nixpkgs/archive/aeb75dba965e790de427b73315d5addf91a54955.tar.gz",
+      "hash": "119lcwpkr9yy49z9fgpq32hp33igc4apbip2y2ppc7hwxs0hwyjk"
+    }
+  },
+  "version": 3
+}