Flex plugin cause RootAccessNotAllowedError in tests 2026.2

IntelliJ Platform
1

My plugin supports using the debugger from the Flex/Flash plugin if the target output is flash/Flex. after bumping intellij target to 2026.2 and the gradle plugin to 2.18.1 i am getting Errors in some of my tests even if they are completely unrelated to the plugin.

How can i fix this ?

ERROR: [testLocalVarDeclaration142b72b6b] Failed to execute task com.intellij.util.indexing.UnindexedFilesScannerExecutorImpl$ScheduledScanningTask@473cd8ad
com.intellij.openapi.vfs.newvfs.impl.VfsRootAccess$VfsRootAccessNotAllowedError: File accessed outside allowed roots: jar://.........../.intellijPlatform/sandbox/Haxe-plugin/IU-2026.2/plugins-test/flex/lib/flex.jar!/com/intellij/lang/javascript/flex/library/ECMAScript.js2;

Here’s some of the xml and build config i am using.

platformPlugins = com.intellij.flex:262.8665.176, OpenGL-Plugin:1.1.6, com.intellij.classic.ui:262.8665.173, intellij.git.commit.modal:262.8665.97

plugin.xml

<depends optional="true" config-file="flex-debugger-support.xml">com.intellij.flex</depends>

flex-debugger-support.xml

<idea-plugin>
  <extensions defaultExtensionNs="com.intellij">
    <plugins.haxe.module.config implementation="com.intellij.plugins.haxe.runner.debugger.HaxeFlexSDKExtension"/>
    <flex.breakpoint.type.provider
        implementation="com.intellij.plugins.haxe.runner.debugger.HaxeBreakpointType$HaxeBreakpointTypeProvider"/>
  </extensions>
</idea-plugin>
2

My solution if anyone else finds this post and need a workaround.

add a line of allowRootAccess with PluginsPath before the fixture.setUp();

VfsRootAccess.allowRootAccess(getTestRootDisposable(), PathManager.getPluginsPath());