Unable to debug Quarkus Dev Mode: JDWP transport load error (dt_shmem not found) with 2025.3

[ToniChaz]

I am experiencing an issue when trying to start Quarkus Dev Mode with debugging enabled using the Quarkus Tools plugin. The process fails immediately with a JDWP fatal error indicating that no transports were initialized. As a result, debugging does not work.

This occurs when running on Windows 11 with WSL2 (Ubuntu 22.04). The configuration was generated automatically by Quarkus Tools.

Environment:

• Host OS: Windows 11
• WSL2: Ubuntu 22.04
• WSL version: 2.6.2.0
• Kernel version: 6.6.87.2-1
• WSLg version: 1.0.71
• MSRDC version: 1.2.6353
• Direct3D version: 1.611.1-81528511
• DXCore version: 10.0.26100.1-240331-1435.ge-release
• Windows version: 10.0.26100.6899
• Java version: graalvm-21 (WSL) java version "21.0.1"
• Quarkus Tools plugin version: 2.3.0
• Configuration created with Quarkus Dev Mode

IntelliJ IDEA 2025.3
Build #IU-253.28294.334, built on December 5, 2025
Source revision: f50d587f27abb
Runtime version: 21.0.8+9-b1163.69 amd64 (JCEF 137.0.17)
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Toolkit: sun.awt.windows.WToolkit
Windows 11.0
GC: G1 Young Generation, G1 Concurrent GC, G1 Old Generation
Memory: 4096M
Cores: 8
Registry:
ide.experimental.ui=true
Non-Bundled Plugins:
com.intellij.notebooks.core (253.28294.337)
com.intellij.debugger.collections.visualizer (253.28294.336)
com.intellij.spring (253.28294.351)
com.github.nizienko.SpaceInvaders (1.1.4)
com.redhat.devtools.intellij.telemetry (1.2.1.62)
Batch Scripts Support (1.0.13)
CMD Support (1.0.5)
net.sf.opk.avro-schema-support (243.0.2)
com.redhat.devtools.lsp4ij (0.19.0)
org.editorconfig.editorconfigjetbrains (253.28294.335)
com.intellij.javaee (253.28294.336)
intellij.jupyter (253.28294.337)
com.redhat.devtools.intellij.quarkus (2.3.0)
com.github.copilot (1.5.61-243)
com.intellij.mcpServer (253.28294.336)
MavenRunHelper (4.30.0-IJ2022.2)
Kotlin: 253.28294.334-IJ

In older versions of IntelliJ it works!

Error output:

/bin/sh /tmp/obmdUK/bin/mvn -Didea.version=2025.3 -Dmaven.ext.class.path=/tmp/AIoWRqmaven-event-listener.jar -Didea.modules.paths.file=/tmp/fT2UQYidea-cc82c3872751-mvn.properties -Djansi.passthrough=true -Dstyle.color=always -Ddebug=52302 -Dmaven.repo.local=/home/toni/.m2/repository quarkus:dev
FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_LOAD(196)
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x9767e4]  jni_FatalError+0x74
C  [libjdwp.so+0x10773]  jniFatalError.constprop.0+0xb3
C  [libjdwp.so+0x1099f]  debugInit_exit+0x6f
C  [libjdwp.so+0x10d37]  initialize+0x2d7
C  [libjdwp.so+0x11680]  cbEarlyVMInit+0xd0
V  [libjvm.so+0xae8224]  JvmtiExport::post_vm_initialized()+0x394
V  [libjvm.so+0xeaf8c0]  Threads::create_vm(JavaVMInitArgs*, bool*)+0x8a0
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
ERROR: transport library not found: dt_shmem
ERROR: JDWP Transport dt_shmem failed to initialize, TRANSPORT_LOAD(509)
JDWP exit error AGENT_ERROR_TRANSPORT_LOAD(196): No transports initialized [open/src/jdk.jdwp.agent/share/native/libjdwp/debugInit.c:687]
V  [libjvm.so+0x977d9e]  JNI_CreateJavaVM+0x4e
C  [libjli.so+0x42cb]  JavaMain+0x8b
C  [libjli.so+0x7e49]  ThreadJavaMain+0x9

Additional notes:
It appears that the plugin is generating a debug configuration that attempts to use the dt_shmem transport, which is not available on Linux environments such as WSL2. As a result, the JVM cannot initialize JDWP and the process aborts.

Please let me know if additional logs or configuration files are required.

[angelozerr]

Please try https://github.com/redhat-developer/intellij-quarkus#testing-nightly-builds and tell me if it is working better

[ToniChaz]

Hi @angelozerr the error disappears with nightly builds and if I choose socket transport (attached image), but the application still doesn't start. The last logs that appear are these:

Disconnected from the target VM, address: '127.0.0.1:57033', transport: 'socket'
Listening for transport dt_socket at address: 57032
ERROR: transport error 202: bind failed: Address already in use
ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510)

[angelozerr]

Have you checked that you have not an another Quarkus application which is started?

If you don't start your Quarkus application and you access to localhost:8080, have you some page which are displayed?

[ToniChaz]

I have nothing else running from Quarkus and it's not accessing the application. I think two debug sessions are starting, one with the plugin and another with IntelliJ. This happens with the latest IntelliJ 2025.3 update.

[angelozerr]

JetBrains changes every time their behavior. With 2025.2 it didn't work and nighty should fix the issue (could you try it please). I have not tested with 2025.3

[ToniChaz]

It worked with the 2025.2.5 version I had previously.

[angelozerr]

That's too bad -( I need to investigate again what JetBrains has changed.

Thanks for your feedback.

[angelozerr]

@ToniChaz I have tested with 2025.3 (on Windows OS) and even if I have those error message

Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=IBM437
Listening for transport dt_socket at address: 55621
ERROR: transport error 202: recv error: Software caused connection abort
Listening for transport dt_socket at address: 55621
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::allocateMemory has been called by io.netty.util.internal.PlatformDependent0$2 (file:/C:/Users/AngeloZerr/.m2/repository/io/netty/netty-common/4.1.128.Final/netty-common-4.1.128.Final.jar)
WARNING: Please consider reporting this to the maintainers of class io.netty.util.internal.PlatformDependent0$2
WARNING: sun.misc.Unsafe::allocateMemory will be removed in a future release

It is working?

[angelozerr]

@ToniChaz when https://github.com/redhat-developer/intellij-quarkus/actions/runs/20192151366 will be finished could you re-install nighty build and tell me if it is working better?

[ToniChaz]

@angelozerr I created a new, clean project to test. The application starts correctly, but I get the following error in the debugger tab and it doesn't work.

Application:

/bin/sh ./mvnw -Didea.version=2025.3 -Dmaven.ext.class.path=/tmp/ymzOxmmaven-event-listener.jar -Didea.modules.paths.file=/tmp/yLALacidea-9ca973767-mvn.properties -Djansi.passthrough=true -Dstyle.color=always -Ddebug=50373 -Dmaven.repo.local=/home/toni/.m2/repository quarkus:dev
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
Listening for transport dt_socket at address: 50374
Connected to the target VM, address: '127.0.0.1:50374', transport: 'socket'
[INFO] Scanning for projects...
[INFO] 
[INFO] ----------------------< org.acme:getting-started >----------------------
[INFO] Building getting-started 1.0.0-SNAPSHOT
[INFO]   from pom.xml
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- quarkus:3.30.3:dev (default-cli) @ getting-started ---
[INFO] Invoking resources:3.3.1:resources (default-resources) @ getting-started
[INFO] Copying 1 resource from src/main/resources to target/classes
[INFO] Invoking quarkus:3.30.3:generate-code (default) @ getting-started
[INFO] Invoking compiler:3.14.1:compile (default-compile) @ getting-started
[INFO] Nothing to compile - all classes are up to date.
[INFO] Invoking resources:3.3.1:testResources (default-testResources) @ getting-started
[INFO] skip non existing resourceDirectory /home/toni/Projects/quarkus/getting-started/src/test/resources
[INFO] Invoking quarkus:3.30.3:generate-code-tests (default) @ getting-started
[INFO] Invoking compiler:3.14.1:testCompile (default-testCompile) @ getting-started
[INFO] Nothing to compile - all classes are up to date.
Picked up JAVA_TOOL_OPTIONS: -Dfile.encoding=UTF-8
Listening for transport dt_socket at address: 50373
Press [e] to edit command line args (currently ''), [h] for more options>
Tests paused
Press [e] to edit command line args (currently ''), [r] to resume testing, [h] for more options>
Press [e] to edit command line args (currently ''), [r] to resume testing, [h] for more options>
Press [e] to edit command line args (currently ''), [r] to resume testing, [o] Toggle test output, [h] for more options>
__  ____  __  _____   ___  __ ____  ______ 
 --/ __ \/ / / / _ | / _ \/ //_/ / / / __/ 
 -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \   
--\___\_\____/_/ |_/_/|_/_/|_|\____/___/   
2025-12-15 08:59:05,077 INFO  [io.quarkus] (Quarkus Main Thread) getting-started 1.0.0-SNAPSHOT on JVM (powered by Quarkus 3.30.3) started in 4.070s. Listening on: http://localhost:8080
2025-12-15 08:59:05,080 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2025-12-15 08:59:05,081 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [cdi, rest, smallrye-context-propagation, vertx]

Debuger:

Error running 'getting-started (Remote)'
Unable to open debugger port (localhost:50373): java.net.ConnectException "Connection refused: connect"

It appears that the port the debugger is trying to connect to is incorrect.

Thanks!

[angelozerr]

@ToniChaz in the console you should see an inlay hint (Attach debugger) on the right of

• Listening for transport dt_socket at address: 50374
• Listening for transport dt_socket at address: 50373

Could you click on it and tell me if it is working?

[ToniChaz]

Yes, it works.

[angelozerr]

When you click on Listening for transport dt_socket at address: 50373 ?, right?

[ToniChaz]

Yes, I've attached an image.