swift-application-variant-task-graph.png...

  compileTestVariantCpp -> linkTestVariant -> installTestVariant -> runTestVariant [dir=back, style=dashed]
  compileTestVariantCpp[label=<compile<i>Variant</i>Cpp>]
  linkTestVariant[label=<link<i>Variant</i>>]
  installTestVariant[label=<installTest<i>Variant</i>>]
  runTestVariant[label=<runTest<i>Variant</i>>]

cpp-unit-test-variant-task-graph.png...

        repository {
            id('org.test:moduleB:1.0') {
                variant('customVariant1') {
                    attribute 'format', 'custom'
                    artifact 'variant1'
                }
                variant('customVariant2') {
                    attribute 'format', 'custom'
                    artifact 'variant2'
                }
            }
        }

        when:

           - Variant org.example:nyvu:1.0 variant greenElementsCapability2 has attributes {color=green}

   > Could not resolve project :.
     Required by:
         project :
      > Multiple incompatible variants of org.example:pi2e5:1.0 were selected:
           - Variant org.example:pi2e5:1.0 variant blueElementsCapability1 has attributes {color=blue}

                }
            }
        }
    }

    def "can select both main variant and test fixtures of a single component"() {
        given:
        repository {
            'org:foo:1.0' {
                variant('api') {}
                variant('runtime') {}
                variant('test-fixtures') {
                    artifact('test-fixtures')

        variant.dependencies[1].group == 'org'
        variant.dependencies[1].module == 'bar'
        variant.dependencies[1].version == null
        variant.dependencies[1].prefers == '2.0'
        variant.dependencies[1].strictly == null
        variant.dependencies[1].rejectsVersion == []

        variant.dependencies[2].group == 'org'
        variant.dependencies[2].module == 'baz'

        variant.dependencies[1].group == 'org'
        variant.dependencies[1].module == 'bar'
        variant.dependencies[1].version == null
        variant.dependencies[1].prefers == '1.0'
        variant.dependencies[1].strictly == null
        variant.dependencies[1].rejectsVersion == []

        variant.dependencies[2].group == 'org'
        variant.dependencies[2].module == 'baz'

     *
     * @since 4.5
     */
    void allVariants(Action<? super VariantMetadata> action);

    /**
     * Add a rule for adding a new empty variant to the component.
     *
     * @param name a name for the variant
     * @param action the action to populate the variant
     *
     * @since 6.0
     */
    void addVariant(String name, Action<? super VariantMetadata> action);

    /**

        def variant = variants.find { it.name == name }
        if (variant == null) {
            variant = new VariantMetadataSpec(name)
            variants << variant
        }
        spec.delegate = variant
        spec.resolveStrategy = Closure.DELEGATE_FIRST
        spec()
    }