update-scripts/version-info: init

Writes a version-info.toml file.

update-scripts/default.nix

@@ -17,4 +17,5 @@ lib.fix (self: {
   none-ls-builtins = pkgs.callPackage ./none-ls.nix { };
   rust-analyzer-options = pkgs.callPackage ./rust-analyzer { };
   lspconfig-servers = pkgs.callPackage ./nvim-lspconfig { };
+  version-info = pkgs.callPackage ./version-info { };
 })

update-scripts/version-info/default.nix

@@ -0,0 +1,36 @@
+{
+  lib,
+  writers,
+  runCommand,
+}:
+let
+  inherit (builtins)
+    all
+    match
+    attrNames
+    ;
+  inherit (lib)
+    importJSON
+    ;
+
+  lockFile = importJSON ../../flake.lock;
+  nixpkgsLock =
+    # Assert there is only one nixpkgs node
+    assert all (node: match "nixpkgs_[0-9]+" node == null) (attrNames lockFile.nodes);
+    lockFile.nodes.nixpkgs.original;
+
+  info = {
+    inherit (lib.trivial) release;
+    nixpkgs_rev = lib.trivial.revisionWithDefault (throw "nixpkgs revision not available");
+    unstable = lib.strings.hasSuffix "-unstable" nixpkgsLock.ref;
+  };
+in
+runCommand "version-info.toml" { } ''
+  (
+    echo "# DO NOT MODIFY!"
+    echo "# This file was generated by ${
+      lib.strings.removePrefix (toString ../.. + "/") (toString ./default.nix)
+    }"
+    cat ${writers.writeTOML "version-info.toml" info}
+  ) > $out
+''