NullPointerException when launching SDBG

[Raphaël Flores]

Hello,

I've just installed the plugin on a long running project (old infrastructure), but I'm not able to launch it on my platform:

$ uname -a
Linux urgi235 3.18.3-201.fc21.x86_64 #1 SMP Mon Jan 19 15:59:31 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

$ java -version
java version "1.7.0_67"
Java(TM) SE Runtime Environment (build 1.7.0_67-b01)
Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

I've tried to use several version nof Google Chrome (40, beta, unstable) and of Chromium:
Version 40.0.2214.115 (64-bit), Version 41.0.2272.64 beta (64-bit) and Version 42.0.2305.3 dev (64-bit) for Chrome.

Version 40.0.2214.91 Russian Fedora (64-bit) and Version 39.0.2171.71 Russian Fedora (64-bit) for Chromium (even if with v39 I had some profile problem at browser startup).

I've enabled the trace and here are the logs:

| Worker-12 | 2015-02-23 15:37:13.343 | com.github.sdbg.debug.core | /browser/launching | com.github.sdbg.debug.core.util.Trace | trace | 45 | Trying to load Chrome from system property chrome.location=/usr/bin/google-chrome-unstable |
| Worker-12 | 2015-02-23 15:37:13.345 | com.github.sdbg.debug.core | /browser/launching | com.github.sdbg.debug.core.util.Trace | trace | 45 | => Found, location is a file, this is assumed to be the Chrome executable |
| Worker-12 | 2015-02-23 15:37:14.051 | com.github.sdbg.debug.core | /browser/launching | com.github.sdbg.debug.core.util.Trace | trace | 45 | Found: [Nouvel onglet,chrome://newtab/,ws://null:54432devtools/page/EE460CD0-32FA-4EC6-AC8A-7F1E0893DC8B] |
| Worker-12 | 2015-02-23 15:37:14.051 | com.github.sdbg.debug.core | /browser/launching | com.github.sdbg.debug.core.util.Trace | trace | 45 | Choosing: [Nouvel onglet,chrome://newtab/,ws://null:54432devtools/page/EE460CD0-32FA-4EC6-AC8A-7F1E0893DC8B] |
| Thread-14 | 2015-02-23 15:37:14.399 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | Error from command id 3: {"message":"DOM agent needs to be enabled first.","code":-32000} |
| Thread-14 | 2015-02-23 15:37:14.476 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.476 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.477 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.478 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.478 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.479 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:14.725 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: DOM.childNodeCountUpdated |
| Thread-14 | 2015-02-23 15:37:14.777 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: DOM.childNodeCountUpdated |
| Thread-14 | 2015-02-23 15:37:14.777 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: DOM.childNodeCountUpdated |
| Thread-14 | 2015-02-23 15:37:14.777 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: DOM.childNodeCountUpdated |
| Thread-14 | 2015-02-23 15:37:14.778 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: DOM.childNodeCountUpdated |
| Thread-14 | 2015-02-23 15:37:29.069 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:29.069 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:29.070 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:29.070 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:29.071 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:29.071 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.frameAttached |
| Thread-14 | 2015-02-23 15:37:39.432 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.interstitialShown |
| Thread-14 | 2015-02-23 15:37:40.662 | com.github.sdbg.debug.core | /wireProtocol | com.github.sdbg.debug.core.util.Trace | trace | 45 | unhandled notification: Page.interstitialHidden |
Exception in thread "Thread-14" java.lang.NullPointerException
        at com.github.sdbg.integration.jdt.JDTBreakpointPathResolver.getPath(JDTBreakpointPathResolver.java:22)
        at com.github.sdbg.debug.core.internal.webkit.model.BreakpointManager.getBreakpointPath(BreakpointManager.java:423)
        at com.github.sdbg.debug.core.internal.webkit.model.BreakpointManager.addBreakpoint(BreakpointManager.java:331)
        at com.github.sdbg.debug.core.internal.webkit.model.BreakpointManager.breakpointAdded(BreakpointManager.java:143)
        at com.github.sdbg.debug.core.internal.webkit.model.BreakpointManager.handleGlobalObjectCleared(BreakpointManager.java:307)
        at com.github.sdbg.debug.core.internal.webkit.model.WebkitDebugTarget$5.debuggerGlobalObjectCleared(WebkitDebugTarget.java:383)
        at com.github.sdbg.debug.core.internal.webkit.protocol.WebkitDebugger.handleDebuggerNotification(WebkitDebugger.java:676)
        at com.github.sdbg.debug.core.internal.webkit.protocol.WebkitDebugger$1.handleNotification(WebkitDebugger.java:195)
        at com.github.sdbg.debug.core.internal.webkit.protocol.WebkitConnection.processNotification(WebkitConnection.java:402)
        at com.github.sdbg.debug.core.internal.webkit.protocol.WebkitConnection.processWebSocketMessage(WebkitConnection.java:330)
        at com.github.sdbg.debug.core.internal.webkit.protocol.WebkitConnection$1.onMessage(WebkitConnection.java:172)
        at de.roderick.weberknecht.WebSocketReceiver.run(WebSocketReceiver.java:65)

Any hint for solving this problem?

Thanks for all.

[Ivan Markov]

Thanks for the detailed info. The NPE is thrown because something really unexpected happens: there is a Java breakpoint which is somehow missing information about its Java class/type.

I will write some null checks that will prevent this from happening (even though the root cause of this is unclear to me).

In the meantime, until a new beta build is released,maybe you could try to remove ALL breakpoints from your Breakpoints view and try to re-launch SDBG/Chrome again.

[Raphaël Flores]

Hi Ivan, Thanks for the trick, you got it, deleting breakpoints allowed to make SDBG working, even if it prompted me the source files to use for debugging the first time, but I can now debug into Eclipse.

Nice job!! o/