Need Help: GWT 2.12.2 / Java 17 / Tomcat 10.1.48 – SDBG Client Debugging Issue

[Shahram Zadeh]

Hello everyone,

After quite a bit of work, I was finally able to set up a Maven project with three modules (client, shared, and server) using GWT 2.12.2, Java 17, and Tomcat 10.1.48.
Everything builds, runs, and debugs correctly in Eclipse — except for one issue: when I hit a breakpoint in the client code, SDBG opens an uneditable copy of the Java source. I can navigate through it but not edit.
I’ve tried multiple classpath and source-path adjustments, but no luck so far. Even ChatGPT and Gemini couldn’t find a working fix.

Any ideas or solutions would be truly appreciated!

Best

Shahram...

[Atul Vishwakarma]

Subject: Solution for SDBG Read-Only Source Issue in GWT 2.12.2 Maven Project

Hello everyone,

I wanted to follow up on the debugging issue where SDBG opens read-only copies of client code when hitting breakpoints in our GWT 2.12.2 Maven project with Eclipse.

After some research, I've found several potential solutions that should resolve this problem:

## Quick Fix - Launch Configuration Source Path

The most common solution is adjusting the Eclipse debug configuration:

1. Go to **Debug Configurations** (right-click your launch config)

2. Navigate to the **Source** tab

3. Click **Add** → **Java Project** → Select the **client module**

4. **Important**: Ensure the client project is at the **top** of the source lookup path

5. Remove any duplicate workspace entries that might be interfering

## Additional Solutions to Try

### Verify GWT Module Configuration

Ensure your GWT module XML includes:

```xml

<source path="client"/>

```

### Maven Plugin Configuration

Check that your `pom.xml` has the source directory properly configured:

```xml

<sourceDirectory>src/main/java</sourceDirectory>

```

### Eclipse Project Structure

- Verify `src/main/java` is listed as a source folder in **Java Build Path** → **Source**

- Confirm output folder points to `target/classes`

### Clean Rebuild Approach

If the above doesn't work, try this reset:

1. Clean all projects (**Project** → **Clean...**)

2. Delete `.classpath`, `.project`, and `.settings` from all modules

3. Reimport as Maven projects

4. Restart Eclipse

### Add Compiler Argument

As a last resort, add this to your GWT compiler arguments:

```

-src src/main/java

```

## Root Cause

The issue occurs when Eclipse's source lookup finds compiled class files or JARs before locating the actual source files. The key is prioritizing the client module's source directory in the lookup path.

Please let me know if any of these solutions work for your setup, or if you discover alternative fixes. Happy to discuss further!

Best regards

[Shahram Zadeh]

Hi Atul and everyone,

The very first solution resolved the issue right away. I really appreciate the quick response — you saved me a lot of time. 

Best,

Shahram...

-------------------------------------------------------------------------------------------

## Quick Fix - Launch Configuration Source Path

The most common solution is adjusting the Eclipse debug configuration:

1. Go to **Debug Configurations** (right-click your launch config)

2. Navigate to the **Source** tab

3. Click **Add** → **Java Project** → Select the **client module**

4. **Important**: Ensure the client project is at the **top** of the source lookup path

5. Remove any duplicate workspace entries that might be interfering

[eliasb...@gmail.com]

I am probably late to the party but I have fallen victim of the same kind of intricacies.

Classpath manipulation and consequently class loading order can be critical in such situations.

I have used Maven to control the classpath and drive the class loading order successfully in my projects.

Editing the Eclipse launch configurations can be equally important but quite infrequent.