Tom Tresansky <******@****.***> 1712091018 -0400

        assertSuggestsReviewingAlgorithm()
        assertSuggestsViewingDocs("Ambiguity errors are explained in more detail at https://docs.gradle.org/${GradleVersion.current().version}/userguide/variant_model.html#sub:variant-ambiguity.")

[[sec:resolving-variant-aware-errors]]
=== Variant Selection Errors

Sometimes a selection error happens at the <<variant_model.adoc#understanding-variant-selection,variant selection level>>.
Have a look at the <<variant_model.adoc#sec:variant-select-errors,dedicated section>> to understand these errors and how to resolve them.

[[sub:resolving-unsafe-configuration-resolution-errors]]

Examples of variants each Java components typically offers are _api_ and _runtime_ variants.
Others examples are JDK8 and JDK11 variants.
For more information, see the section on <<variant_model.adoc#understanding-variant-selection,variant selection>>.

[[sub:terminology_attribute]]
== Variant Attribute

Attributes are used to identify and select <<#sub:terminology_variant,variants>>.

The main difference between writing rules and defining dependencies and artifacts in the build script is that component metadata rules, following the structure of Gradle Module Metadata, operate on <<variant_model.adoc#understanding-variant-selection,variants>> directly.

Gradle identifies a variant of a dependency uniquely by its set of <<variant_model.adoc#sec:abm_configuration_attributes,attributes>>.
The `java-api` variant of a dependency is the variant identified by the `org.gradle.usage` attribute with value `java-api`.

When Gradle resolves a configuration, the <<variant_model.adoc#sec:abm_configuration_attributes,attributes>> on the resolved configuration determine the _requested attributes_.

====

In this example, we use a convention plugin `myproject.xctest-conventions` to expose the test results from a project to Gradle's <<variant_model.adoc#understanding-variant-selection,variant aware dependency management engine>>.

The plugin declares a consumable `binaryTestResultsElements` configuration that represents the binary test results of the `test` task.

[[sec:variant_aware_substitutions]]
=== Substituting a dependency with another variant

Gradle's dependency management engine is <<variant_model.adoc#understanding-variant-selection,variant-aware>> meaning that for a single component, the engine may select different artifacts and transitive dependencies.

// See the License for the specific language governing permissions and
// limitations under the License.

[[variant_attributes]]
= Working with Variant Attributes

As explained in the section on <<variant_model.adoc#sec:variant-aware-matching,variant aware matching>>, attributes give semantics to variants and are used by Gradle's dependency management engine to select the best matching variant.

However, the consumer has to explicitly tell which configuration it depends on, which is something we want to avoid in _variant aware resolution_.
In fact, we also <<variant_model.adoc#understanding-variant-selection, have explained>> that it is possible for a consumer to express requirements using _attributes_ and that the producer should provide the appropriate outgoing variants using attributes too.