* Make copy-tarballs.sh work on release.nix.

svn path=/nixpkgs/trunk/; revision=19834

maintainers/scripts/eval-release.nix

@@ -0,0 +1,20 @@
+# Evaluate `release.nix' like Hydra would (i.e. call each job
+# attribute with the expected `system' argument).  Too bad
+# nix-instantiate can't to do this.
+
+let
+
+  lib = (import ../.. {}).lib;
+
+  rel = removeAttrs (import ../../pkgs/top-level/release.nix) ["tarball"];
+
+  maybe = x: let y = builtins.tryEval x; in if y.success then y.value else null;
+
+  call = attrs: lib.flip lib.mapAttrs attrs
+    (n: v: builtins.trace n (
+      if builtins.isFunction v then maybe (v { system = "i686-linux"; })
+      else if builtins.isAttrs v then call v
+      else null
+    ));
+
+in call rel