Clarify IntelliJ IDEA Jar Hell fix
@@ -106,11 +106,19 @@ IntelliJ users can automatically configure their IDE: `gradle idea`
then `File->New Project From Existing Sources`. Point to the root of
the source directory, select
`Import project from external model->Gradle`, enable
-`Use auto-import`. Additionally, in order to run tests directly from
-IDEA 2017.1 and above it is required to disable IDEA run launcher,
-which can be achieved by adding `-Didea.no.launcher=true`
-[JVM option](https://intellij-support.jetbrains.com/hc/en-us/articles/206544869-Configuring-JVM-options-and-platform-properties)
-
+`Use auto-import`. In order to run tests directly from
+IDEA 2017.2 and above, it is required to disable the IDEA run launcher in order to avoid
+`idea_rt.jar` causing "jar hell". This can be achieved by adding the
+`-Didea.no.launcher=true` [JVM
+option](https://intellij-support.jetbrains.com/hc/en-us/articles/206544869-Configuring-JVM-options-and-platform-properties).
+Alternatively, `idea.no.launcher=true` can be set in the
+[`idea.properties`](https://www.jetbrains.com/help/idea/file-idea-properties.html)
+file which can be accessed under Help > Edit Custom Properties (this will require a
+restart of IDEA). For IDEA 2017.3 and above, in addition to the JVM option, you will need to go to
+`Run->Edit Configurations...` and change the value for the `Shorten command line` setting from
+`user-local default: none` to `classpath file`. You may also need to [remove `ant-javafx.jar` from your
+classpath](https://github.com/elastic/elasticsearch/issues/14348) if that is
+reported as a source of jar hell.
The Elasticsearch codebase makes heavy use of Java `assert`s and the
test runner requires that assertions be enabled within the JVM. This
