== Publish a Build Scan

The best way to learn more about what your build is doing behind the scenes, is to publish a link:https://scans.gradle.com[build scan].
To do so, just run Gradle with the `--scan` flag.

[listing.terminal.sample-command]
----
\$ ./gradlew build --scan

BUILD SUCCESSFUL in 0s
${tasksExecuted.raw} actionable tasks: ${tasksExecuted.raw} executed

        @Mutate
        void set(Bean bean) {
            bean.value = "changed"
        }
    }

    def "when targeting by type, can have rule use more general type than target"() {
        given:
        def mmType = ModelTypes.modelMap(Bean)

        registry
            .registerModelMap("beans", Bean) {
                it.registerFactory(Bean) { new Bean(name: it) }

            }

            def configureGradleLifecycle() {
                SomeBean bean = new SomeBean()
                ${type} value = ${reference}
                bean.value = ${reference}
                gradle.lifecycle.beforeProject {
                    println "this.value = " + value
                    println "bean.value = " + bean.value
                }
            }

            configureGradleLifecycle()

// checkSimilarDistribution returns success if the mean and stddev of the
// two statsResults are similar.
func (sr *statsResults) checkSimilarDistribution(expected *statsResults) error {
	if !nearEqual(sr.mean, expected.mean, expected.closeEnough, expected.maxError) {
		s := fmt.Sprintf("mean %v != %v (allowed error %v, %v)", sr.mean, expected.mean, expected.closeEnough, expected.maxError)
		fmt.Println(s)
		return errors.New(s)

In Gradle 4.3 and above, you can create a build scan using the `--scan` command line option:

[listing.terminal]
----
$ gradle build --scan
----

For older Gradle versions, the
https://docs.gradle.com/build-scan-plugin/#getting_set_up[Build Scan Plugin User Manual]
explains how to enable build scans.

At the end of your build, Gradle displays a URL where you can find your build scan:

----
BUILD SUCCESSFUL in 2s

        SomeBean bean = new SomeBean();

        Xpp3Dom config = toConfig("<file>test</file>");

        DefaultBeanConfigurationRequest request = new DefaultBeanConfigurationRequest();
        request.setBean(bean).setConfiguration(config);

        configurator.configureBean(request);

        assertEquals(Paths.get("test"), bean.file);
    }

    @Test

    <a class="badge" href="https://dpeuniversity.gradle.com/app/courses/b5069222-cfd0-4393-b645-7a2c713853d5/" target="_blank">
        <span class="badge-type button--blue">LEARN</span>
        <span class="badge-text">How to Use Build Scans&nbsp;&nbsp;&nbsp;&gt;</span>
    </a>
</div>
++++

A build scan is a *representation of metadata captured* as you run your build.

image::gradle-basic-1.png[]

== Build Scans

      DoubleMath.mean(Double.POSITIVE_INFINITY);
      fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException expected) {
    }
  }

  @GwtIncompatible // DoubleMath.mean
  public void testMean_intVarargs() {
    assertEquals(-13.75, DoubleMath.mean(11, -22, 44, -88), 1.0e-10);
    assertEquals(11.0, DoubleMath.mean(11), 1.0e-10);
  }

  @GwtIncompatible // DoubleMath.mean

        output.contains "Input property 'bean'"

        output.contains "Input property 'bean.input'"
        output.contains "Input property 'bean.nestedBean'"
        output.contains "Input file property 'bean.inputDir'"
        output.contains "Input file property 'bean.nestedBean.inputFile'"
        output.contains "Output file property 'bean.outputDir'"
    }

	dst.Write(b)
	return err
}

func appendIndent(dst, src []byte, prefix, indent string) ([]byte, error) {
	origLen := len(dst)
	scan := newScanner()
	defer freeScanner(scan)
	needIndent := false
	depth := 0
	for _, c := range src {
		scan.bytes++
		v := scan.step(scan, c)
		if v == scanSkipSpace {
			continue
		}
		if v == scanError {
			break
		}