anchor.diff:  # enable security debugging
   ./gradlew test -Dtests.jvm.argline="-Djava.security.debug=access,failure"
   ------------------------------
  -
  -== Backwards Compatibility Tests
  -
  -Running backwards compatibility tests is disabled by default since it
  -requires a release version of elasticsearch to be present on the test system.
  -To run backwards compatibility tests untar or unzip a release and run the tests
  -with the following command:
  -
  ----------------------------------------------------------------------------
  -./gradlew test -Dtests.filter="@backwards" -Dtests.bwc.version=x.y.z -Dtests.bwc.path=/path/to/elasticsearch -Dtests.security.manager=false
  ----------------------------------------------------------------------------
  -
  -Note that backwards tests must be run with security manager disabled.
  -If the elasticsearch release is placed under `./backwards/elasticsearch-x.y.z` the path
  -can be omitted:
  -
  ----------------------------------------------------------------------------
  -./gradlew test -Dtests.filter="@backwards" -Dtests.bwc.version=x.y.z -Dtests.security.manager=false
  ----------------------------------------------------------------------------
  -
  -To setup the bwc test environment execute the following steps (provided you are
  -already in your elasticsearch clone):
  -
  ----------------------------------------------------------------------------
  -$ mkdir backwards && cd backwards
  -$ curl -O https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.2.1.tar.gz
  -$ tar -xzf elasticsearch-1.2.1.tar.gz
  ----------------------------------------------------------------------------
   
   == Running verification tasks
   
  
positive.code: . Push both branches to your remote repository.
  . Run the tests with `./gradlew check -Dtests.bwc.remote=${remote} -Dtests.bwc.refspec.5.x=index_req_bwc_5.x`.
  
  == Skip fetching latest
  
  For some BWC testing scenarios, you want to use the local clone of the
  repository without fetching latest. For these use cases, you can set the system
  
negative.code: == Testing backwards compatibility
  
  Backwards compatibility tests exist to test upgrading from each supported version
  to the current version. To run them all use:
  
  -------------------------------------------------
  ./gradlew bwcTest
  -------------------------------------------------
  
  A specific version can be tested as well. For example, to test bwc with
  version 5.3.2 run:
  
  -------------------------------------------------
  ./gradlew v5.3.2#bwcTest
  -------------------------------------------------
  
  Tests are ran for versions that are not yet released but with which the current version will be compatible with.
  These are automatically checked out and built from source.
  See link:./buildSrc/src/main/java/org/elasticsearch/gradle/VersionCollection.java[VersionCollection]
  and link:./distribution/bwc/build.gradle[distribution/bwc/build.gradle] 
  for more information.
  
  When running `./gradlew check`, minimal bwc checks are also run against compatible versions that are not yet released.
  
  ==== BWC Testing against a specific remote/branch
  
  Sometimes a backward compatibility change spans two versions. A common case is a new functionality
  that needs a BWC bridge in an unreleased versioned of a release branch (for example, 5.x).
  