Flash Builder Mac Breakpoints generate NullPointerExceptions

Question

I have a complex, pre-existing Actionscript project to work with at my current employer. The project was originally created with FlashDevelop, which is not an option for me as a Mac user. I can successfully build the project and deploy it to others. It runs as expected.

The problem is with the debugging. I cannot make it work. I believe users of Flash Builder on Windows machines have successfully debugged this project on their machine. I can build and debug projects I make myself. It's THIS particular project, or something about how it is constructed, that is preventing debugging from occurring.

Symptoms:

• Starting the program via the Debug button runs the program, but the presence of a breakpoint causes the program to freeze the browser where it is running
• Removing the breakpoint or stopping the debugger allows the browser to unfreeze and continue normally
• At no point does the breakpoint actually get reached and break into the debugger
• Attempting to place a breakpoint during execution results in an internal error: java.lang.NullPointerException

• Example log message from within .metadata/.log

  java.lang.NullPointerException
  !STACK 0
  !MESSAGE Error processing debugger commands
  !ENTRY com.adobe.flexbuilder.project 4 43 2011-08-24 13:35:07.404
    at java.lang.Thread.run(Thread.java:680)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread.run(FlexDebugTarget.java:793)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread.eventLoop(FlexDebugTarget.java:732)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread$1.run(FlexDebugTarget.java:752)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread.access$7(FlexDebugTarget.java:642)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread.advanceStateMachine(FlexDebugTarget.java:668)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget$FdbThread.installDeferredBreakpoints(FlexDebugTarget.java:637)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget.access$4(FlexDebugTarget.java:1006)
    at com.adobe.flexbuilder.debug.model.FlexDebugTarget.instantiateBreakpoint(FlexDebugTarget.java:1012)
    at com.adobe.flexbuilder.debug.breakpoints.FlexLineBreakpoint.instantiate(FlexLineBreakpoint.java:465)
    at com.adobe.flexbuilder.debug.breakpoints.FlexLineBreakpoint.findSourceFiles(FlexLineBreakpoint.java:412)
  

Attempted Fixes:

• Cleaned project
• Cleared browser cache
• Tried different browsers (Yes, I have the debug player)
• Deleted .metadata
• Deleted workspace
• Reinstalled Flash Builder
• Reinstalled Debug Flash Player
• Restarted Mac
• Tried a different SDK
• Reordered Java preference for both 32 and 64 bit configurations
• Removed symlinks from project configuration (that is, symlinks are no longer needed to correctly find the build or run location)
• Cleared Flash logs
• Ensured no more than one version of the program was getting compiled (so it can't actually be running from another location)
• Explicitly turned on debugging through compiler argument: -debug=true
• Changing just about every relevant and lots of irrelevant settings within Project Properties

Project Details:

• Interestingly, clicking on Actionscript Applications in the Project Properties results in Flash Builder immediately becoming unresponsive
• Uses third-party libraries for functionality that may or may not be Debug builds
• Uses third-party code for functionality that is included with the rest of the code via Actionscript Build Path > Source path (note that this folder must be included explicitly for this project even though the path included is already in the source directory)
• Runs from a local web server, accessing local database using a custom domain that is not "localhost" nor an IP address (changed for Chrome cookie issues), rather it looks like http://programname.local/
• Launch configuration starts the web browser at the correct local url (as opposed to starting up from a file), probably irrelevant
• There is one additional compiler argument that simply creates a global, compile-time constant, probably irrelevant
• Source and project directories contain svn repository folders and files, probably irrelevant
• I have an NDA, so I can only talk about the project and its structure, I can't post code

Configuration:

• Mac OS 10.6.8
• Flash Builder 4 (through CS5)
• Flex SDK 4.0 and 4.5.1

Answer 1

Figured it out. Our app uses a preloader which I had always gotten from others. I had assumed it was compiled to debug because I always got my copy from our debug server. I didn't fully understand how it worked or what it was doing.

Due to a Flash error in the preloader, this morning I was forced to compile it for the first time. Compiling it normally (as debug) I realized the problem with non-debug swfs loading debug swfs might apply here.

Breakpoints worked as expected once I correctly compiled the preloader and fixed its bug. Apparently our preloader is doing the actual loading of the main app. Flash Builder apparently can't handle this setup (non-debug loading a debug swf), whereas FlashDevelop apparently can.

Answer 2

Have you tried restarting your Mac?

I feel your pain, and your list of attempted fixes are what I'd try first :)

I had a similar situation to this and after hours of cursing Adobe I restarted my Mac and that solved it (probably some kind of memory error).