-
Notifications
You must be signed in to change notification settings - Fork 500
Open
Description
This appears to be related to eclipse-jdt/eclipse.jdt.core#3298. I'm not sure when this changed but as of the update released yesterday I am now getting the following error in my logs any time I try to work on my Minecraft mod projects (e.g. glektarssza/minecraft-gtnh-customizer):
!ENTRY org.eclipse.jdt.core.manipulation 4 0 2025-10-29 09:43:37.638
!MESSAGE Error in JDT Core during AST creation
!STACK 0
java.lang.IllegalStateException: Missing system library
at org.eclipse.jdt.core.dom.ASTParser.checkForSystemLibrary(ASTParser.java:311)
at org.eclipse.jdt.core.dom.ASTParser.getClasspath(ASTParser.java:269)
at org.eclipse.jdt.core.dom.ASTParser.internalCreateASTCached(ASTParser.java:1395)
at org.eclipse.jdt.core.dom.ASTParser.lambda$1(ASTParser.java:1274)
at org.eclipse.jdt.internal.core.JavaModelManager.cacheZipFiles(JavaModelManager.java:5709)
at org.eclipse.jdt.core.dom.ASTParser.internalCreateAST(ASTParser.java:1274)
at org.eclipse.jdt.core.dom.ASTParser.createAST(ASTParser.java:918)
at org.eclipse.jdt.core.manipulation.CoreASTProvider$1.run(CoreASTProvider.java:294)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
at org.eclipse.jdt.core.manipulation.CoreASTProvider.createAST(CoreASTProvider.java:286)
at org.eclipse.jdt.core.manipulation.CoreASTProvider.getAST(CoreASTProvider.java:199)
at org.eclipse.jdt.ls.core.internal.JDTUtils.getAst(JDTUtils.java:1953)
at org.eclipse.jdt.ls.core.internal.handlers.SemanticTokensHandler.full(SemanticTokensHandler.java:45)
at org.eclipse.jdt.ls.core.internal.handlers.JDTLanguageServer.lambda$57(JDTLanguageServer.java:1205)
at org.eclipse.jdt.ls.core.internal.BaseJDTLanguageServer.lambda$0(BaseJDTLanguageServer.java:87)
at java.base/java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:667)
at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:504)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:511)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1450)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:2019)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:187)
To replicate the issue:
- Ensure you have Git LFS installed properly (see this comment on redhat-developer/vscode-java#4218 for why).
- Clone the repository.
- Install the extensions outlined in the
Enabled Extensions Informationsection below. - Copy the appropriate template VSCode settings from
./templates/vscode/from inside the repository above into your./.vscode/settings.jsonfile inside the repository above. - Replace the Java paths inside the copied templates to a version of Java 21.
- Ensure your
JAVA_HOMEenvironment variable is set to a version of Java 17. - Run
./gradlew setupDecompWorkspaceinside the repository above. - Run
./gradlew buildinside the repository above. - Run
./gradlew eclipseinside the repository above. - Try to get autocompletion in any file.
- Observe the issue.