Bug 3749 - Debugger crashes with error: System.NullReferenceException: Object reference not set to an instance of an object
Summary: Debugger crashes with error: System.NullReferenceException: Object reference ...
Status: RESOLVED FIXED
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: Debugger ()
Version: Trunk
Hardware: PC Linux
: --- normal
Target Milestone: ---
Assignee: Jeffrey Stedfast
URL:
Depends on:
Blocks:
 
Reported: 2012-03-04 13:26 UTC by Miro Radenovic
Modified: 2017-08-13 18:48 UTC (History)
2 users (show)

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

Notice (2018-05-24): bugzilla.xamarin.com is now in read-only mode.

Please join us on Visual Studio Developer Community and in the Xamarin and Mono organizations on GitHub to continue tracking issues. Bugzilla will remain available for reference in read-only mode. We will continue to work on open Bugzilla bugs, copy them to the new locations as needed for follow-up, and add the new items under Related Links.

Our sincere thanks to everyone who has contributed on this bug tracker over the years. Thanks also for your understanding as we make these adjustments and improvements for the future.


Please create a new report on Developer Community or GitHub with your current version information, steps to reproduce, and relevant error messages or log files if you are hitting an issue that looks similar to this resolved bug and you do not yet see a matching new report.

Related Links:
Status:
RESOLVED FIXED

Description Miro Radenovic 2012-03-04 13:26:35 UTC
Hello,
I'm using NUnit inside monodevelop and I run my tests using:
Run Test with => Mono Soft Debugger

the debugger sometimes unpredictability crashes during step-into, throwing:

System.NullReferenceException: Object reference not set to an instance of an object
  at Mono.Debugging.Soft.SoftDebuggerSession.HandleBreakEventSet (Mono.Debugger.Soft.Event[] es, Boolean dequeuing) [0x0013e] in /home/myoMint/Development/monodevelop/main/src/addins/MonoDevelop.Debugger.Soft/Mono.Debugging.Soft/SoftDebuggerSession.cs:1195 
  at Mono.Debugging.Soft.SoftDebuggerSession.HandleEventSet (Mono.Debugger.Soft.EventSet es) [0x00071] in /home/myoMint/Development/monodevelop/main/src/addins/MonoDevelop.Debugger.Soft/Mono.Debugging.Soft/SoftDebuggerSession.cs:1128 
  at Mono.Debugging.Soft.SoftDebuggerSession.EventHandler () [0x0002d] in /home/myoMint/Development/monodevelop/main/src/addins/MonoDevelop.Debugger.Soft/Mono.Debugging.Soft/SoftDebuggerSession.cs:1065 

I cannot repeat the issue because as I said ,it crashes "randomly".
Let me know how to provide you more details, if possible.

I'm using the latest source code taken from github (git clone git://github.com/mono/monodevelop.git) and i have built with ./configure --profile=dist
I'm running monodevelop from the directory that holds the build (make run)

Here is the full version info:
MonoDevelop 2.8.8.1
Installation UUID: 68aee599-a056-4f7a-9191-c9426a2aa1fe
Runtime:
	Mono 2.10.5 (Debian 2.10.5-1) (64-bit)
	GTK 2.24.6
	GTK# (2.12.0.0)
Build information:
	Git revision: c83c3e02ca6d62e2552a99b8ac18ba5e9b186b78-dirty
	Build date: 2012-03-04 14:28:28+0000
Operating System:
	Linux
	Linux pingu 3.0.0-12-generic #20-Ubuntu SMP Fri Oct 7 14:56:25 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
Loaded assemblies:
Mono.Cecil.Mdb                             0.9.4.0        /home/myoMint/Development/monodevelop/main/build/bin/Mono.Cecil.Mdb.dll
MonoDevelop.Debugger.Gdb                   2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Debugger.Gdb/build/MonoDevelop.Debugger.Gdb.dll
MonoDevelop.Debugger.Soft.AspNet           0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger.Soft/MonoDevelop.Debugger.Soft.AspNet.dll
MonoDevelop.Debugger.Soft.Moonlight        0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger.Soft/MonoDevelop.Debugger.Soft.Moonlight.dll
MonoDevelop.Debugger.Soft                  2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger.Soft/MonoDevelop.Debugger.Soft.dll
Mono.Debugger.Soft                         0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger.Soft/Mono.Debugger.Soft.dll
Mono.Debugging.Soft                        0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger.Soft/Mono.Debugging.Soft.dll
mdhost                                     1.0.0.0        /home/myoMint/Development/monodevelop/main/build/bin/mdhost.exe
System.Runtime.Remoting                    4.0.0.0        /usr/lib/mono/gac/System.Runtime.Remoting/4.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
NUnitRunner                                0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/NUnitRunner.dll
MonoDeveloperExtensions_nunit              0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDeveloperExtensions/MonoDeveloperExtensions_nunit.dll
MonoDevelop.AspNet.Mvc                     2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.AspNet.Mvc/MonoDevelop.AspNet.Mvc.dll
MonoDevelop.CodeMetrics                    2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.CodeMetrics/MonoDevelop.CodeMetrics.dll
MonoDevelop.VersionControl.Subversion.Unix 2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/MonoDevelop.VersionControl.Subversion.Unix.dll
MonoDevelop.VersionControl.Subversion      2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/MonoDevelop.VersionControl.Subversion.dll
Sharpen                                    1.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/Sharpen.dll
NGit                                       1.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/NGit.dll
MonoDevelop.VersionControl.Git             2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/MonoDevelop.VersionControl.Git.dll
MonoDevelop.DocFood                        1.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.DocFood.dll
gconf-sharp                                2.24.0.0       /usr/lib/mono/gac/gconf-sharp/2.24.0.0__35e10195dab3c99f/gconf-sharp.dll
MonoDevelop.HexEditor                      2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.HexEditor.dll
MonoDevelop.AssemblyBrowser                2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.AssemblyBrowser.dll
MonoDevelop.Database.Sql.MySql             2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Sql.MySql.dll
MonoDevelop.TextTemplating                 2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.TextTemplating/MonoDevelop.TextTemplating.dll
MonoDevelop.Database.Sql.SqlServer         2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Sql.SqlServer.dll
MonoDevelop.Database.Sql.Sqlite            2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Sql.Sqlite.dll
MonoDevelop.Database.Sql.Npgsql            2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Sql.Npgsql.dll
MonoDevelop.Database.Designer              2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Designer.dll
MonoDevelop.Database.Query                 2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Query.dll
MonoDevelop.Database.Components            2.6.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Components.dll
MonoDevelop.Database.Sql                   2.2.0.0        /home/myoMint/Development/monodevelop/extras/MonoDevelop.Database/build/MonoDevelop.Database.Sql.dll
MonoDevelop.WebReferences                  2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.WebReferences/MonoDevelop.WebReferences.dll
MonoDevelop.Gettext                        2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Gettext/MonoDevelop.Gettext.dll
ChangeLogAddIn                             2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/ChangeLogAddIn/ChangeLogAddIn.dll
MonoDevelop.CBinding                       2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/BackendBindings/MonoDevelop.CBinding.dll
PyBinding                                  2.6.0.0        /home/myoMint/Development/monodevelop/extras/PyBinding/build/PyBinding.dll
MonoDevelop.ValaBinding                    2.6.0.0        /home/myoMint/Development/monodevelop/extras/ValaBinding/build/MonoDevelop.ValaBinding.dll
JavaBinding                                2.6.0.0        /home/myoMint/Development/monodevelop/extras/JavaBinding/build/JavaBinding.dll
ILAsmBinding                               2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/BackendBindings/ILAsmBinding.dll
OldNRefactory                              2.1.1.0        /home/myoMint/Development/monodevelop/main/build/bin/OldNRefactory.dll
ICSharpCode.NRefactory                     1.0.4446.27670 /home/myoMint/Development/monodevelop/main/build/bin/ICSharpCode.NRefactory.dll
MonoDevelop.Projects.Formats.MSBuild       1.0.0.0        /home/myoMint/Development/monodevelop/main/build/bin/MonoDevelop.Projects.Formats.MSBuild.exe
MonoDevelop.Autotools                      2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Autotools/MonoDevelop.Autotools.dll
MonoDevelop.MsVisualStudio                 2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.MsVisualStudio/MonoDevelop.MsVisualStudio.dll
MonoDevelop.VBNetBinding                   2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/BackendBindings/MonoDevelop.VBNetBinding.dll
MonoDevelop.CSharpBinding                  2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/BackendBindings/MonoDevelop.CSharpBinding.dll
MonoDevelop.Refactoring                    2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Refactoring/MonoDevelop.Refactoring.dll
ICSharpCode.SharpZipLib                    2.84.0.0       /usr/lib/mono/gac/ICSharpCode.SharpZipLib/2.84.0.0__1b03e6acf1164f73/ICSharpCode.SharpZipLib.dll
Mono.Security                              4.0.0.0        /usr/lib/mono/gac/Mono.Security/4.0.0.0__0738eb9f132ed756/Mono.Security.dll
MonoDevelop.GtkCore                        2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.GtkCore/MonoDevelop.GtkCore.dll
libsteticui                                0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.GtkCore/libsteticui.dll
libstetic                                  0.0.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.GtkCore/libstetic.dll
MonoDevelop.Deployment.Linux               2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Deployment/MonoDevelop.Deployment.Linux.dll
nunit.util                                 2.4.8.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/nunit.util.dll
nunit.framework                            2.4.8.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/nunit.framework.dll
nunit.core.interfaces                      2.4.8.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/nunit.core.interfaces.dll
nunit.core                                 2.4.8.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/nunit.core.dll
MonoDevelop.NUnit                          2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/NUnit/MonoDevelop.NUnit.dll
MonoDeveloperExtensions                    2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDeveloperExtensions/MonoDeveloperExtensions.dll
Mono.Debugging                             0.0.0.0        /home/myoMint/Development/monodevelop/main/build/bin/Mono.Debugging.dll
pango-sharp                                2.12.0.0       /usr/lib/mono/gac/pango-sharp/2.12.0.0__35e10195dab3c99f/pango-sharp.dll
MonoDevelop.VersionControl                 2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/VersionControl/MonoDevelop.VersionControl.dll
MonoDevelop.Moonlight                      2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Moonlight/MonoDevelop.Moonlight.dll
MonoDevelop.AspNet                         2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.AspNet/MonoDevelop.AspNet.dll
MonoDevelop.XmlEditor                      2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.XmlEditor/MonoDevelop.XmlEditor.dll
MonoDevelop.SourceEditor2                  2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.SourceEditor2.dll
MonoDevelop.Debugger                       2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Debugger/MonoDevelop.Debugger.dll
MonoDevelop.Deployment                     2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.Deployment/MonoDevelop.Deployment.dll
MonoDevelop.DesignerSupport                2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/MonoDevelop.DesignerSupport/MonoDevelop.DesignerSupport.dll
monodoc                                    1.0.0.0        /usr/lib/mono/gac/monodoc/1.0.0.0__0738eb9f132ed756/monodoc.dll
System.Drawing                             4.0.0.0        /usr/lib/mono/gac/System.Drawing/4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
gnome-vfs-sharp                            2.24.0.0       /usr/lib/mono/gac/gnome-vfs-sharp/2.24.0.0__35e10195dab3c99f/gnome-vfs-sharp.dll
gnome-sharp                                2.24.0.0       /usr/lib/mono/gac/gnome-sharp/2.24.0.0__35e10195dab3c99f/gnome-sharp.dll
GnomePlatform                              2.6.0.0        /home/myoMint/Development/monodevelop/main/build/AddIns/GnomePlatform.dll
Mono.Cecil                                 0.9.4.0        /home/myoMint/Development/monodevelop/main/build/bin/Mono.Cecil.dll
System.Configuration                       4.0.0.0        /usr/lib/mono/gac/System.Configuration/4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
Mono.Cairo                                 2.0.0.0        /usr/lib/mono/gac/Mono.Cairo/2.0.0.0__0738eb9f132ed756/Mono.Cairo.dll
gdk-sharp                                  2.12.0.0       /usr/lib/mono/gac/gdk-sharp/2.12.0.0__35e10195dab3c99f/gdk-sharp.dll
Mono.TextEditor                            1.0.0.0        /home/myoMint/Development/monodevelop/main/build/bin/Mono.TextEditor.dll
atk-sharp                                  2.12.0.0       /usr/lib/mono/gac/atk-sharp/2.12.0.0__35e10195dab3c99f/atk-sharp.dll
glib-sharp                                 2.12.0.0       /usr/lib/mono/gac/glib-sharp/2.12.0.0__35e10195dab3c99f/glib-sharp.dll
gtk-sharp                                  2.12.0.0       /usr/lib/mono/gac/gtk-sharp/2.12.0.0__35e10195dab3c99f/gtk-sharp.dll
Mono.Posix                                 4.0.0.0        /usr/lib/mono/gac/Mono.Posix/4.0.0.0__0738eb9f132ed756/Mono.Posix.dll
Mono.Addins                                0.6.0.0        /usr/lib/mono/gac/Mono.Addins/0.6.0.0__0738eb9f132ed756/Mono.Addins.dll
Mono.Addins.Setup                          0.6.0.0        /usr/lib/mono/gac/Mono.Addins.Setup/0.6.0.0__0738eb9f132ed756/Mono.Addins.Setup.dll
System.Xml                                 4.0.0.0        /usr/lib/mono/gac/System.Xml/4.0.0.0__b77a5c561934e089/System.Xml.dll
System.Xml.Linq                            4.0.0.0        /usr/lib/mono/gac/System.Xml.Linq/4.0.0.0__b77a5c561934e089/System.Xml.Linq.dll
System.Core                                4.0.0.0        /usr/lib/mono/gac/System.Core/4.0.0.0__b77a5c561934e089/System.Core.dll
System                                     4.0.0.0        /usr/lib/mono/gac/System/4.0.0.0__b77a5c561934e089/System.dll
MonoDevelop.Core                           2.6.0.0        /home/myoMint/Development/monodevelop/main/build/bin/MonoDevelop.Core.dll
MonoDevelop.Ide                            2.6.0.0        /home/myoMint/Development/monodevelop/main/build/bin/MonoDevelop.Ide.dll
MonoDevelop                                2.6.0.0        /home/myoMint/Development/monodevelop/main/build/bin/MonoDevelop.exe
mscorlib                                   4.0.0.0        /usr/lib/mono/4.0/mscorlib.dll
Comment 1 Jeffrey Stedfast 2012-03-04 18:01:29 UTC
thanks, this should be fixed in git now.