JUnit Plug-in Test Ignores Target Platform in Ecli

I have some problems getting JUnit plug-in tests to work using Eclipse Neon M7 and I'd really like input from anybody out there who uses tests (there has to be somebody, right?).

Whenever I start a test that works in Eclipse Luna (but didn't in Mars, which I assumed was a bug) and continues to work using Tycho I get the following exception:

!SESSION 2016-05-11 10:25:41.456 -----------------------------------------------
eclipse.buildId=unknown
java.version=1.8.0_73
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_US
Framework arguments:  -version 3 -port 60297 -testLoaderClass org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader -loaderpluginname org.eclipse.jdt.junit4.runtime -classNames org.acme.test.test.core.ActivatorTest -application org.eclipse.pde.junit.runtime.uitestapplication -testApplication org.eclipse.ui.ide.workbench -testpluginname test.core
Command-line arguments:  -os win32 -ws win32 -arch x86 -consoleLog -version 3 -port 60297 -testLoaderClass org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader -loaderpluginname org.eclipse.jdt.junit4.runtime -classNames org.acme.test.test.core.ActivatorTest -application org.eclipse.pde.junit.runtime.uitestapplication -testApplication org.eclipse.ui.ide.workbench -data C:\workspaces\MyWorkspace/../junit-workspace -dev file:C:/workspaces/MyWorkspace/.metadata/.plugins/org.eclipse.pde.core/pde-junit/dev.properties -os win32 -ws win32 -arch x86 -consoleLog -testpluginname test.core

!ENTRY org.eclipse.pde.junit.runtime 4 0 2016-05-11 10:25:42.373
!MESSAGE FrameworkEvent ERROR
!STACK 0
org.osgi.framework.BundleException: Could not resolve module: org.eclipse.pde.junit.runtime [81]
  Unresolved requirement: Require-Bundle: org.eclipse.core.runtime; bundle-version="[3.11.0,4.0.0)"

    at org.eclipse.osgi.container.Module.start(Module.java:434)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1582)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1561)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1533)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.dispatchEvent(ModuleContainer.java:1476)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.dispatchEvent(ModuleContainer.java:1)
    at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
    at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:340)

!ENTRY org.eclipse.pde.junit.runtime 2 0 2016-05-11 10:25:42.719
!MESSAGE Could not resolve module: org.eclipse.pde.junit.runtime [81]
  Unresolved requirement: Require-Bundle: org.eclipse.core.runtime; bundle-version="[3.11.0,4.0.0)"


!ENTRY org.eclipse.osgi 4 0 2016-05-11 10:25:42.720
!MESSAGE Application error
!STACK 1
java.lang.RuntimeException: Application "org.eclipse.pde.junit.runtime.uitestapplication" could not be found in the registry. The applications available are: org.eclipse.ant.core.antRunner, org.eclipse.ui.ide.workbench, org.eclipse.help.base.infocenterApplication, org.eclipse.help.base.helpApplication, org.eclipse.help.base.indexTool, org.acme.test.rxp.rxpdemo, org.eclipse.equinox.app.error.
    at org.eclipse.equinox.internal.app.EclipseAppContainer.startDefaultApp(EclipseAppContainer.java:248)
    at org.eclipse.equinox.internal.app.MainApplicationLauncher.run(MainApplicationLauncher.java:29)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:382)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:236)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1386)

Clearly it's not a Eclipse bug at this point, but I'm doing something wrong. There is no indication what kind of plug-ins are started in the test, but judging from the version ranges I assume it's the wrong ones again - the plug-ins of the running Eclipse instance instead of the plug-ins defined in the workspace's target platform.

Still the launch configuration claims the later target platform is used.

How do I configure a plug-in unit test so that it will take the currently active target platform?

The problem here is that Eclipse 4.4 (Luna, 2014) and below had a version of org.eclipse.core.runtime that was compatible with the host Eclipse version of org.eclipse.pde.junit.runtime. That changed with 4.5 when the dependency increased.

As you have correctly concluded that the configuration is pointing at the wrong org.eclipse.pde.junit.runtime. This is probably due to uncleared configuration state. Ensure that the configuration is being cleared, so you don't run with a stale version. That is ensure that Clear the configuration area before launching is checked in the Configuration tab of launch configuration.

You can see exactly what PDE has resolved as the configured bundles by looking at ${workspace_loc}/.metadata/.plugins/org.eclipse.pde.core/pde-junit/org.eclipse.equinox.simpleconfigurator/bundles.info (location specified in Configuration tab of launch configuration)