The build session state is managed by the `BuildSessionState` class.
An instance is created at the start of a Gradle invocation and discarded at the end of that invocation.

The build session state also includes "cross session" state that is shared with any "nested" sessions that need to be created.
This only happens when the `GradleBuild` task is used. You can mostly ignore the distinction between "cross session" and "build session" state.

    val testTaskOptionsParameterName = "testTaskOptions"
    val daemon = true
    applyDefaultSettings(os, arch, buildJvm = BuildToolBuildJvm, timeout = 0)

    // Show all failed tests here, since that is what we are interested in
    failureConditions.supportTestRetry = false

    val extraParameters = functionalTestExtraParameters("RerunFlakyTest", os, arch, "%$testJvmVersionParameter%", "%$testJvmVendorParameter%")

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user facing features, what will the API look like?
* What test cases should it have? What could go wrong?
* How will it roughly be implemented? We'll happily provide code pointers to save you time.

#### JVM platform

This is a platform that builds on the core and software platforms to add support for developing software that runs on the JVM.
This includes software that is implemented using Java, Kotlin or some other JVM language.

This platform provides specific support for Java, Groovy and Scala, and includes the foojay toolchain plugin. 

#### Extensibility platform

### JVM platform

This is a platform that builds on the core and software platforms to add support for developing software that runs on the JVM.
This includes software that is implemented using Java, Kotlin or some other JVM language.

This platform provides specific support for Java, Groovy and Scala, and includes the foojay toolchain plugin.

### Extensibility platform

 */
plugins {
    `java-library`
    `java-test-fixtures`
    groovy
    id("gradlebuild.dependency-modules")
}

// The below mimics what the java-library plugin does, but creating a library of test fixtures instead.

sourceSets.matching { it.name.endsWith("Test") }.all {

    "BUILD_TYPE_ID",
    "JPROFILER_HOME",

    "LANG",
    "LANGUAGE",
    // It is possible to have many LC_xxx variables for different aspects of the locale. However, LC_ALL overrides all of them, and it is what CI uses.
    "LC_ALL",
    "LC_CTYPE",

    "JDK_10",
    "JDK_10_0",
    "JDK_10_0_x64",
    "JDK_10_x64",
    "JDK_11",
    "JDK_11_0",
    "JDK_11_0_x64",
    "JDK_11_x64",
    "JDK_12",

        // If SanityCheck fails, Gradleception will definitely fail because the last build step is also sanityCheck
        dependsOn(RelativeId(SanityCheck.buildTypeId(model)))
    }

    /*
     To avoid unnecessary rerun, what we do here is a bit complicated:

     1. Build a Gradle distribution with a fixed timestamp and hash it, but never use this distribution.

package gradlebuild.basics


/**
 * This is the definition of what constitutes the Gradle public API.
 *
 * A type is part of the Gradle public API if and only if its FQCN matches {@link #includes} and does not match {@link #excludes}.
 */
// NOTE: If you update this, please also change .idea/scopes/Gradle_public_API.xml
// and also change `avoiding_gradle_internal_apis` section in `src/docs/userguide/authoring-builds/authoring_maintainable_build_scripts.adoc`

 *
 * WARNING: Every val in here must not change for they same daemon. If it does, changes will go undetected,
 *          since this whole object is kept in the classloader between builds.
 *          Anything that changes must be in a val with a get() method that recomputes the value each time.
 */
object BuildEnvironment {

    /**
     * A selection of environment variables injected into the environment by the `codeql-env.sh` script.
     */