Bug 21040 - ERR_UNLOADED while debugging assembly in loaded AppDomain
Summary: ERR_UNLOADED while debugging assembly in loaded AppDomain
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: Debugger ()
Version: unspecified
Hardware: PC Windows
: Normal normal
Target Milestone: ---
Assignee: Jeffrey Stedfast
Depends on:
Reported: 2014-07-02 08:56 UTC by Adam Rzepka
Modified: 2015-01-07 01:17 UTC (History)
6 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Adam Rzepka 2014-07-02 08:56:12 UTC
I believe that https://bugzilla.xamarin.com/show_bug.cgi?id=18100 is not the same bug, because of different stack and steps to reproduce.

1. Create simple app "tester.exe":
    class MainClass
        public static void Main(string[] args)
            Console.WriteLine("Set breakpoint here");

2. Create second app, which will load and execute the first one a few times:

    class MainClass
        public static void Main(string[] args)
            for (int i = 0; i < 10; ++i)
                AppDomain domain = AppDomain.CreateDomain("tester.exe");

3. In XamarinStudio set breakpoint in first app and start debugging.
4. Hit breakpoint two times, then watch the error occuring:
  Mono.Debugger.Soft.CommandException: Debuggee returned error code ERR_UNLOADED.
   at Mono.Debugger.Soft.VirtualMachine.ErrorHandler(Object sender, ErrorHandlerEventArgs args)
   at Mono.Debugger.Soft.Connection.SendReceive(CommandSet command_set, Int32 command, PacketWriter packet)
   at Mono.Debugger.Soft.Connection.Domain_GetAssemblies(Int64 id)
   at Mono.Debugger.Soft.AppDomainMirror.GetAssemblies()
   at Mono.Debugging.Soft.SoftDebuggerAdaptor.GetType(EvaluationContext ctx, String name, Object[] typeArgs)
   at Mono.Debugging.Evaluation.ObjectValueAdaptor.GetType(EvaluationContext ctx, String name)
   at Mono.Debugging.Soft.SoftDebuggerBacktrace.CreateStackFrame(StackFrame frame, Int32 frameIndex)
   at Mono.Debugging.Soft.SoftDebuggerBacktrace.GetStackFrames(Int32 firstIndex, Int32 lastIndex)
   at Mono.Debugging.Client.Backtrace.GetFrame(Int32 n)
   at Mono.Debugging.Client.Backtrace..ctor(IBacktrace serverBacktrace)
   at Mono.Debugging.Soft.SoftDebuggerSession.GetThreadBacktrace(ThreadMirror thread)
   at Mono.Debugging.Soft.SoftDebuggerSession.HandleBreakEventSet(Event[] es, Boolean dequeuing)
   at Mono.Debugging.Soft.SoftDebuggerSession.HandleEventSet(EventSet es)
   at Mono.Debugging.Soft.SoftDebuggerSession.EventHandler()
5. Debugger and mono stuck.
Comment 1 Zoltan Varga 2014-07-02 09:02:17 UTC
This is probably a dup of:
Comment 2 Adam Rzepka 2014-07-02 09:23:42 UTC
Unfortunately, fix for https://bugzilla.xamarin.com/show_bug.cgi?id=19922 didn't help. After f29c547b659c03126989622302dd664e0a29983f error still occurs.
Comment 3 Zoltan Varga 2014-07-03 15:22:56 UTC
I can reproduce this with XS 5.1 (build 462).
This looks like an xs problem, it is calling GetAssemblies () on an AppDomainMirror whose domain has been unloaded.
Comment 4 Ram Chandra 2014-10-30 14:35:29 UTC
Zoltan is able to reproduce this issue. As per comment 3, I am changing it's status from new to confirm.
Comment 5 David Karlaš 2015-01-07 01:17:15 UTC
Changes were made recently in domains handling for debugger. I was able to reproduce this in stable but not in master Hence marking as resolved fixed.