Java Gradle Plugin project created from `gradle init` using "new API and behavior" causes broken Gradle API dependency

[ergh99]

Extension Name: vscode-gradle
Extension Version: 3.17.1 and 3.17.2025111402
OS Version: Windows 10
VSCode version: 1.106.3
Gradle: 9.2.1

Describe the bug
see redhat-developer/vscode-java#3260
Same behavior is occurring but none of the suggestions / workarounds have any effect. Only commenting out the generated line (gradlePlugin.testSourceSets.add(sourceSets["functionalTest"])) causes the import issue to be resolved.

To Reproduce
Use gradle init with the following options:

• Type of project: 3: java-gradle-plugin
• DSL: 2: Kotlin
• Java target version: 21
• Generate build using new APIs and behavior: yes

Expected behavior
The project compiles from VSCode tooling.

Screenshots

Output from "Gradle for Java"
[info] [gradle-server] Gradle Server started, listening on 62094
[info] Gradle client connected to server
[info] Build file changed: c:\Users\ergh99\Code\records2schema\records2schema-gradle-plugin\plugin\build.gradle.kts
[info] Build file changed: c:\Users\ergh99\Code\records2schema\records2schema-gradle-plugin\plugin\build.gradle.kts

Does the bug still exist if you disable all other extensions?
Yes

[github-actions]

Hi @ergh99, I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

The issue stems from the new “Generate build using new APIs and behavior” flag in Gradle 9. Currently the only workaround is to remove the generated functionalTest source-set registration so that the Java LS can pick up the Gradle API:

• In plugin/build.gradle.kts, comment out or delete:

// gradlePlugin.testSourceSets.add(sourceSets["functionalTest"])

• Alternatively, run gradle init without “new APIs and behavior” (answer “no” to that prompt).

Related issues to follow:

• redhat-developer/vscode-java#3260 • [java-gradle-plugin] Gradle API not resolved when developing Gradle plugins with Java
No workaround beyond commenting out the test source-set line; watch for updates here.

• microsoft/vscode-gradle#1686 • “Gradle for Java plugin breaks with Gradle 9 projects”
Tracks general Gradle 9 support in the Gradle extension.

Other references with low confidence

• microsoft/vscode-gradle#1257 • “Classpath for Gradle API not recognized with developing Gradle plugins using Gradle init”

The team will respond to your issue shortly. I hope these suggestions are helpful in the meantime. If this comment helped you, please give it a 👍. If the suggestion was not helpful or incorrect, please give it a 👎. Your feedback helps us improve!