add integration test for Environment#run_builder

build_tests/simple/run_builder.rb

@@ -0,0 +1,12 @@
+class MyObject < Rscons::Builder
+  def run(options)
+    target, sources, cache, env, vars = options.values_at(:target, :sources, :cache, :env, :vars)
+    env.run_builder(env.builders["Object"], target, sources, cache, vars)
+  end
+end
+
+Rscons::Environment.new do |env|
+  env.add_builder(MyObject.new)
+  env.MyObject("simple.o", "simple.c")
+  env.Program("simple.exe", "simple.o")
+end

spec/build_tests_spec.rb

@@ -631,6 +631,16 @@ EOF
     ]
   end
 
+  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")
+    expect(result.stderr).to eq ""
+    expect(lines(result.stdout)).to eq [
+      "CC simple.o",
+      "LD simple.exe",
+    ]
+  end
+
   context "Directory builder" do
     it "creates the requested directory" do
       test_dir("simple")