Failed to execute java

[tmm1]

Failed to execute Java command to run lsp server. Please ensure that kotlinLSP.jrePathToRunLsp option is set correctly to the JRE installation path.Current value is null

I see this error on macOS and it's very confusing. There are java installations:

❯ /usr/libexec/java_home -V
Matching Java Virtual Machines (3):
    24.0.1 (arm64) "Oracle Corporation" - "OpenJDK 24.0.1" /Users/tmm1/Library/Java/JavaVirtualMachines/openjdk-24.0.1/Contents/Home
    21.0.2 (arm64) "Eclipse Adoptium" - "OpenJDK 21.0.2" /Library/Java/JavaVirtualMachines/temurin-21.jdk/Contents/Home
    17.0.14 (arm64) "JetBrains s.r.o." - "JBR-17.0.14+1-1367.22-nomod 17.0.14" /Users/tmm1/Library/Java/JavaVirtualMachines/jbr-17.0.14/Contents/Home

If I open settings and search for jrePathToRunLsp, it's not clear what value I'm supposed to put in there. The full bin/java path didn't work. The JAVA_HOME didn't work.

[tmm1]

Looks like it is meant to be the JAVA_HOME

kotlin-lsp/kotlin-vscode/src/lspClient.ts

Lines 90 to 107 in 55b91da

	const jrePathForLspSettingName = 'kotlinLSP.jrePathToRunLsp';
	const minimumSupportedJavaVersion = 17
	function getJrePathForKotlinLSP() {
	return vscode.workspace.getConfiguration().get<string>(jrePathForLspSettingName)
	}
	async function getJavaPath(): Promise<string | null> {
	let jrePath = getJrePathForKotlinLSP();
	if (!jrePath) {
	return 'java'
	}
	const javaExecutable = os.platform() === 'win32' ? 'java.exe' : 'java';
	return path.join(jrePath, 'bin', javaExecutable);

I'm not sure why I get an error regardless of the setting

[tmm1]

I tried to run the lsp directly and I see this:

❯ java -classpath 'jetbrains.kotlin-0.253.10629/server/extracted/lib/*' com.jetbrains.ls.kotlinLsp.KotlinLspServerKt --client
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.jetbrains.analyzer.filewatcher.FileWatcher$Companion in an unnamed module (file:/Users/tmm1/.cursor-nightly/extensions/jetbrains.kotlin-0.253.10629/server/extracted/lib/language-server.kotlin-lsp.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

2025-08-24 13:24:57,081 [      0]   INFO - #c.j.l.k.KotlinLspServerKt - idea.config.path=/var/folders/mf/fzhrjgk1677460w2n591kv1h0000gn/T/idea-system17602802841195845138/config
2025-08-24 13:24:57,098 [     17]   INFO - #c.j.l.k.KotlinLspServerKt - idea.system.path=/var/folders/mf/fzhrjgk1677460w2n591kv1h0000gn/T/idea-system17602802841195845138/system
Exception in thread "main" java.lang.reflect.InaccessibleObjectException: Unable to make field private static java.lang.Boolean java.awt.GraphicsEnvironment.headless accessible: module java.desktop does not "opens java.awt" to unnamed module @6fe7aac8
        at java.base/java.lang.reflect.AccessibleObject.throwInaccessibleObjectException(AccessibleObject.java:353)
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:329)
        at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:277)
        at java.base/java.lang.reflect.Field.checkCanSetAccessible(Field.java:179)
        at java.base/java.lang.reflect.Field.setAccessible(Field.java:173)
        at com.jetbrains.ls.kotlinLsp.KotlinLspServerKt.initHeadlessToolkit(KotlinLspServer.kt:171)
        at com.jetbrains.ls.kotlinLsp.KotlinLspServerKt.run(KotlinLspServer.kt:64)
        at com.jetbrains.ls.kotlinLsp.KotlinLspServerKt.main(KotlinLspServer.kt:51)