feat: modernize

packages/repo-lib/lib/common.nix

@@ -0,0 +1,29 @@
+{ nixpkgs }:
+let
+  lib = nixpkgs.lib;
+in
+{
+  inherit lib;
+
+  importPkgs = nixpkgsInput: system: import nixpkgsInput { inherit system; };
+
+  duplicateStrings =
+    names:
+    lib.unique (
+      builtins.filter (
+        name: builtins.length (builtins.filter (candidate: candidate == name) names) > 1
+      ) names
+    );
+
+  mergeUniqueAttrs =
+    label: left: right:
+    let
+      overlap = builtins.attrNames (lib.intersectAttrs left right);
+    in
+    if overlap != [ ] then
+      throw "repo-lib: duplicate ${label}: ${lib.concatStringsSep ", " overlap}"
+    else
+      left // right;
+
+  sanitizeName = name: lib.strings.sanitizeDerivationName name;
+}