Merge pull request #68491 from roberth/fix-dontRecurseIntoAttrs

Fix dontRecurseIntoAttrs + add to lib + doc

lib/attrsets.nix

@@ -473,6 +473,20 @@ rec {
   /* Pick the outputs of packages to place in buildInputs */
   chooseDevOutputs = drvs: builtins.map getDev drvs;
 
+  /* Make various Nix tools consider the contents of the resulting
+     attribute set when looking for what to build, find, etc.
+
+     This function only affects a single attribute set; it does not
+     apply itself recursively for nested attribute sets.
+   */
+  recurseIntoAttrs =
+    attrs: attrs // { recurseForDerivations = true; };
+
+  /* Undo the effect of recurseIntoAttrs.
+   */
+  dontRecurseIntoAttrs =
+    attrs: attrs // { recurseForDerivations = false; };
+
   /*** deprecated stuff ***/
 
   zipWithNames = zipAttrsWithNames;