Extension/services not initializing when running tests in IJ 2026.2 EAP and IPGP 2.16.0

I’m in the process of updating my plugins to be built on the 2026.2 EAPs.

I have the following configured in build.gradle.kts:

kotlin { jvmToolchain(25) }

dependencies {
	intellijPlatform {  
	    intellijIdea("262.7581.18-EAP-SNAPSHOT") { useInstaller = false }
}

intellijPlatform {  
	pluginConfiguration {  
	    ideaVersion {  
		    sinceBuild = "262"
	    }
	}
}

//These were already in place
testFramework(TestFrameworkType.Platform)  
testFramework(TestFrameworkType.Plugin.Java)  
testFramework(TestFrameworkType.JUnit5)

Dependent plugin versions are updated, gradle wrapper is 9.5.0, intellij-platform-gradle-plugin is 2.16.0.
My plugins

  • have dependencies on plugins/modules like com.intellij.java, com.dmarcotte.handlebars, com.intellij.modules.json, com.intellij.swagger, intellij.platform.langInjection to name a few.
  • use plugin model v1 and v2 but all are single-module projects.

Upon running my tests I see log entries like this

07:01:15,508 INFO   llij.ide.plugins.PluginManager - Problems found loading plugins: 
  Plugin 'OpenAPI Specifications' (com.intellij.swagger) has dependency on 'HTTP Client' which cannot be loaded 
  Plugin 'HTTP Client' (com.jetbrains.restClient) has dependency on 'intellij.platform.smRunner' which is not installed 
  Plugin 'JSONPath' (com.intellij.jsonpath) has dependency on 'IDEA CORE' which cannot be loaded 
  Plugin 'JVM Microservices Frameworks' (com.intellij.microservices.jvm) has dependency on 'Java' which cannot be loaded 
  Plugin 'JavaScript and TypeScript' (JavaScript) has dependency on 'intellij.platform.smRunner' which is not installed 
  Plugin 'Java' (com.intellij.java) has dependency on 'IDEA CORE' which cannot be loaded 
  Plugin 'Properties' (com.intellij.properties) has dependency on 'IDEA CORE' which cannot be loaded 
  Plugin 'Handlebars/Mustache' (com.dmarcotte.handlebars) has dependency on 'IDEA CORE' which cannot be loaded 
  Plugin 'WireMock' (com.intellij.wiremock) has dependency on 'JSON' which cannot be loaded 
07:01:15,512 INFO   llij.ide.plugins.PluginManager - Loaded bundled plugins: YAML (262.7581.18), JSON (262.7581.18), Endpoints (262.7581.18), Terminal (262.7581.18), Structure View (262.7581.18), TODO View (262.7581.18), Structural Search (262.7581.18), Markdown (262.7581.18), Aether Dependency Resolver (262.7581.18), Images (262.7581.18), IDEA CORE (262.7581.18) 

and several of these for different plugins and modules

plugin org.jetbrains.kotlin is not resolved 
  └ dependent module intellij.microservices.jvm.kt excluded
  
module intellij.libraries.lucene.common (namespace=jetbrains) is not resolved 
  └ dependent module intellij.spellchecker excluded

What I also see is extensions seemingly not being initialized (or maybe not even loaded), thus not being called, and services not being initialized either, their getInstance() returning null.

The only relevant info I’ve managed to find is Dependencies of bundled plugin `com.intellij.java` missing · Issue #2158 · JetBrains/intellij-platform-gradle-plugin · GitHub , but configuring them (with their latest ids, not with the ones in the issues) doesn’t solve the problem, and it would seem overkill to configure several transitively dependent plugins/modules because I depend on a select few anyways.

I’m guessing there may be some classpath configuration issues here (not sure if related only to the Java plugin, or others too).

Is there something I might be missing in project/build configuration, or is it maybe something that 2.16.0 of the intellij-platform-gradle-plugin is not yet able to handle?

Tool Version
Gradle 9.5.0
IntelliJ Platform Gradle Plugin 2.16.0
IntelliJ EAP EAP 6 (262.7581.18) but have seen issues in EAP 1 too

I put together a small demo project (based on the latest plugin template) to reproduce the issue with a minimal feature set:

Notes:

  • It fails on CI too, so it is not just a local problem.
  • The extension loads and works when running in an actual IDE.

I see that this has been apparently reported under Structure view impl package not found - #14 by jansorg