uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

pkgs/development/ruby-modules/with-packages/test.nix

@@ -0,0 +1,46 @@
+# a generic test suite for all gems for all ruby versions.
+# use via nix-build.
+let
+  pkgs = import ../../../.. {};
+  lib = pkgs.lib;
+  stdenv = pkgs.stdenv;
+
+  rubyVersions = with pkgs; [
+    ruby_2_7
+  ];
+
+  gemTests =
+    (lib.mapAttrs
+      (name: gem: [ name ])
+      pkgs.ruby.gems) //
+    (import ./require_exceptions.nix);
+
+  tests = ruby:
+    lib.mapAttrs (name: gem:
+      let
+        test =
+          if builtins.isList gemTests.${name}
+          then pkgs.writeText "${name}.rb" ''
+                puts "${name} GEM_HOME: #{ENV['GEM_HOME']}"
+                ${lib.concatStringsSep "\n" (map (n: "require '${n}'") gemTests.${name})}
+              ''
+          else pkgs.writeText "${name}.rb" gemTests.${name};
+
+        deps = ruby.withPackages (g: [ g.${name} ]);
+      in stdenv.mkDerivation {
+        name = "test-gem-${ruby.name}-${name}";
+        buildInputs = [ deps ];
+        buildCommand = ''
+          INLINEDIR=$PWD ruby ${test}
+          touch $out
+        '';
+      }
+    ) ruby.gems;
+in
+  stdenv.mkDerivation {
+    name = "test-all-ruby-gems";
+    buildInputs = builtins.foldl' (sum: ruby: sum ++ ( builtins.attrValues (tests ruby) )) [] rubyVersions;
+    buildCommand = ''
+      touch $out
+    '';
+  }