add backwards-compatibility test for Builder#standard_build

build_tests/simple/standard_build.rb

@@ -0,0 +1,17 @@
+class MyCommand < Rscons::Builder
+  def run(target, sources, cache, env, vars)
+    vars = vars.merge({
+      "_TARGET" => target,
+      "_SOURCES" => sources,
+    })
+    command = env.build_command("${CMD}", vars)
+    cmd_desc = vars["CMD_DESC"] || "MyCommand"
+    standard_build("#{cmd_desc} #{target}", target, command, sources, env, cache)
+  end
+end
+
+Rscons::Environment.new do |env|
+  env.add_builder(MyCommand.new)
+  command = %w[gcc -c -o ${_TARGET} ${_SOURCES}]
+  env.MyCommand("simple.o", "simple.c", "CMD" => command)
+end

spec/build_tests_spec.rb

@@ -631,6 +631,7 @@ EOF
     ]
   end
 
+  context "backward compatibility" do
     it "allows a builder to call Environment#run_builder in a non-threaded manner" do
       test_dir("simple")
       result = run_test(rsconsfile: "run_builder.rb")
@@ -662,6 +663,14 @@ EOF
       expect(result.stdout).to match /Failed command was: gcc/
     end
 
+    it "supports builders that call Builder#standard_build" do
+      test_dir("simple")
+      result = run_test(rsconsfile: "standard_build.rb")
+      expect(result.stderr).to eq ""
+      expect(lines(result.stdout)).to eq ["MyCommand simple.o"]
+    end
+  end
+
   context "Directory builder" do
     it "creates the requested directory" do
       test_dir("simple")