lib: add gitSource helper

README.md

@@ -181,6 +181,19 @@ pkgs.mkNginxServer {
 }
 ```
 
+### [`gitSource`](./lib/git-source)
+
+for development package nix files, computes the source set of files tracked by git at the given root
+path
+
+example:
+```nix
+stdenv.mkDerivation {
+  # ...
+  src = gitSource { root = ./.; };
+}
+```
+
 ## development
 
 structure of this repo

default.nix

@@ -9,6 +9,8 @@
     (final: prev: {
       fetchFromSteam = prev.callPackage ./lib/fetchsteam {};
 
+      gitSource = prev.callPackage ./lib/git-source {};
+
       ghidra_headless = prev.ghidra.override {
         openjdk17 = prev.openjdk17_headless;
       };

lib/git-source/default.nix

@@ -0,0 +1,8 @@
+{ lib }: { root }:
+let
+  fs = lib.fileset;
+  sourceFiles = fs.difference
+    (fs.gitTracked root)
+    (fs.fileFilter (file: file.hasExt "nix") root);
+in
+  fs.toSource { inherit root; fileset = sourceFiles; }