Debug error: io.karatelabs.debug.DapServerHandler is not a @Sharable handler, so can't be added or removed multiple times

[j8d]

Getting the error below trying to start a single debug session via CodeLense. It was working fine until yesterday afternoon.

12:06:12.126 [main] INFO com.intuit.karate - Karate version: 1.5.0.RC3
debug server started on port: 34407
12:06:12.855 [nioEventLoopGroup-3-2] WARN i.n.ide.channel.ChannelInitializer - Failed to initialize a channel. Closing: [id: 0x2e6606b3, L:/127.0.0.1:34407 - R:/127.0.0.1:36912]
io.netty.ide.channel.ChannelPipelineException: io.karatelabs.debug.DapServerHandler is not a @sharable handler, so can't be added or removed multiple times.
at io.netty.ide.channel.DefaultChannelPipeline.checkMultiplicity(DefaultChannelPipeline.java:600)
at io.netty.ide.channel.DefaultChannelPipeline.addLast(DefaultChannelPipeline.java:202)
at io.netty.ide.channel.DefaultChannelPipeline.addLast(DefaultChannelPipeline.java:381)
at io.netty.ide.channel.DefaultChannelPipeline.addLast(DefaultChannelPipeline.java:370)
at io.karatelabs.debug.DapServer$1.initChannel(DapServer.java:61)
at io.netty.ide.channel.ChannelInitializer.initChannel(ChannelInitializer.java:129)
at io.netty.ide.channel.ChannelInitializer.handlerAdded(ChannelInitializer.java:112)
at io.netty.ide.channel.AbstractChannelHandlerContext.callHandlerAdded(AbstractChannelHandlerContext.java:1130)
at io.netty.ide.channel.DefaultChannelPipeline.callHandlerAdded0(DefaultChannelPipeline.java:609)
at io.netty.ide.channel.DefaultChannelPipeline.access$100(DefaultChannelPipeline.java:46)
at io.netty.ide.channel.DefaultChannelPipeline$PendingHandlerAddedTask.execute(DefaultChannelPipeline.java:1463)
at io.netty.ide.channel.DefaultChannelPipeline.callHandlerAddedForAllHandlers(DefaultChannelPipeline.java:1115)
at io.netty.ide.channel.DefaultChannelPipeline.invokeHandlerAddedIfNeeded(DefaultChannelPipeline.java:650)
at io.netty.ide.channel.AbstractChannel$AbstractUnsafe.register0(AbstractChannel.java:514)
at io.netty.ide.channel.AbstractChannel$AbstractUnsafe.access$200(AbstractChannel.java:429)
at io.netty.ide.channel.AbstractChannel$AbstractUnsafe$1.run(AbstractChannel.java:486)
at io.netty.ide.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:173)
at io.netty.ide.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:166)
at io.netty.ide.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
at io.netty.ide.channel.nio.NioEventLoop.run(NioEventLoop.java:569)
at io.netty.ide.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.ide.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.ide.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:840)

[ptrthomas]

@j8d thanks, we'll do our best to investigate but this will be hard to replicate.

by any chance did something change in your environment - say like an OS upgrade ? recently Java on the Mac has had some interesting issues.

[j8d]

After messing with it some more, I found out the error occurs when I place a break point in a feature that gets called before the feature I initiate the debug session from. Also, vscode is running on WSL on Windows 10.

Actually, log.feature gets called even before this as it's called from features called from karate-config.js

[ptrthomas]

@j8d thanks we'll tale a look

[ptrthomas]

@j8d can you try the patch release we built from here: https://github.com/karatelabs/vscode-extension/releases/tag/v2.0.5 - it should fix this problem, let me know

by the way you certainly seem to be using JS + Java interop a lot - please be aware of this development: karatelabs/karate#2546

[j8d]

Thank you @ptrthomas - that fix resolved the DapServerHandler error. But, annoyingly, that error was apparently just a red herring for the issue I'm actually facing, It's possible it's an edge case that's not worth investigating, but here's what I've found...

1. Call a feature (classpath:helpers/Okta.feature) from karate-config:

var result = karate.callSingle('classpath:helpers/Okta.feature@referral', config);
config.token = result.token;

2. From that feature (classpath:helpers/Okta.feature), call another feature (classpath:helpers/log.feature):

   • def info = karate.info
   • call read('classpath:helpers/log.feature') info

3. Add a breakpoint to the second feature (log.feature)

4. Start a debug session from a third feature in the runner path (classpath:features/some.feature)

The breakpoint in log.feature will cause the process to hang. It appears to be pausing at the breakpoint but not enabling the options in vscode to continue past it.

[j8d]

Also, when debugging Java...

[ptrthomas]

@j8d yes it may be an edge case. I suspect a second "instance" of a debug session is being created somewhere, but hard to figure out. there's actually a debug log you can switch on, please refer: https://github.com/karatelabs/vscode-extension#troubleshooting - so if you can paste the log or screenshot for that (in DEBUG) that may provide some clues

else I'm voting to close this. unless you have the time to provide a quickstart project where this can be replicated, but I know that can be hard

[j8d]

Replicated in https://github.com/j8d/vscode-extension-issue-22/tree/main/src/test/java/examples/users

users.feature is called from kartate-config.js
users2 is called from users

Add a breakpoint in users2 then debug from users3 and it will hang

[ptrthomas]

@j8d apologies for the delay on this. I think the reason is anything within a JS function currently has to execute within a global JVM lock. this is why this happens for things within karate-config.js because it is a JS function. this problem should be resolved with the work here: karatelabs/karate#2546

so until then any breakpoints within karate-config.js may have this issue. until the lock is released no other JS can be evaluated. in the long term we hope to even support stepping through JS blocks