fully parallelize the Command builder

spec/build_tests_spec.rb

@@ -706,6 +706,21 @@ EOF
     end
   end
 
+  context "Command builder" do
+    it "allows executing an arbitrary command" do
+      test_dir('simple')
+
+      result = run_test(rsconsfile: "command_builder.rb")
+      expect(result.stderr).to eq ""
+      expect(lines(result.stdout)).to eq ["BuildIt simple.exe"]
+      expect(`./simple.exe`).to eq "This is a simple C program\n"
+
+      result = run_test(rsconsfile: "command_builder.rb")
+      expect(result.stderr).to eq ""
+      expect(result.stdout).to eq ""
+    end
+  end
+
   context "Directory builder" do
     it "creates the requested directory" do
       test_dir("simple")

spec/rscons/builders/command_spec.rb

@@ -1,18 +0,0 @@
-module Rscons
-  module Builders
-    describe Command do
-
-      let(:command) { ['pandoc', '-fmarkdown', '-thtml', '-o${_TARGET}', '${_SOURCES}'] }
-      let(:env) {Environment.new}
-      subject {Command.new}
-
-      it "invokes the command to build the target" do
-        expected_cmd = ['pandoc', '-fmarkdown', '-thtml', '-ofoo.html', 'foo.md']
-        expect(subject).to receive(:standard_build).with("PANDOC foo.html", "foo.html", expected_cmd, ["foo.md"], env, :cache)
-        subject.run("foo.html", ["foo.md"], :cache, env,
-                    "CMD" => command, "CMD_DESC" => "PANDOC")
-      end
-
-    end
-  end
-end