Issue with Symbols - can't step into .NET code

Question

I can't make Visual Studio 2010 SP1 step into any .NET Framework class, I've found many guides in internet, but none of them work...

Here's the what output window says:

Step into: Stepping over method without symbols 'System.Collections.Generic.SortedSet<Shared.Optimization.Solution<GaTest.CurveFitSimplex,double>>.Remove'

Here is whole Output window contents:

'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.HostingProcess.Utilities\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.HostingProcess.Utilities.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Windows.Forms\v4.0_4.0.0.0__b77a5c561934e089\System.Windows.Forms.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Drawing\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Drawing.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.HostingProcess.Utilities.Sync\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.HostingProcess.Utilities.Sync.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\assembly\GAC_MSIL\Microsoft.VisualStudio.Debugger.Runtime\10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualStudio.Debugger.Runtime.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\GaTest.vshost.exe', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Core\v4.0_4.0.0.0__b77a5c561934e089\System.Core.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Xml.Linq\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.Linq.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Data.DataSetExtensions\v4.0_4.0.0.0__b77a5c561934e089\System.Data.DataSetExtensions.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\Microsoft.CSharp\v4.0_4.0.0.0__b03f5f7f11d50a3a\Microsoft.CSharp.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_32\System.Data\v4.0_4.0.0.0__b77a5c561934e089\System.Data.dll', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Xml\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.dll', Symbols loaded.
The thread 'vshost.NotifyLoad' (0x1444) has exited with code 0 (0x0).
The thread '<No Name>' (0x3d8) has exited with code 0 (0x0).
The thread '<No Name>' (0x10a8) has exited with code 0 (0x0).
The thread 'vshost.LoadReference' (0xc40) has exited with code 0 (0x0).
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\GaTest.exe', Symbols loaded.
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Users\Lu4\documents\visual studio 2010\Projects\Estimator\GaTest\bin\Debug\Shared.dll', Symbols loaded.
Step into: Stepping over method without symbols 'System.Collections.Generic.SortedSet<Shared.Optimization.Solution<GaTest.CurveFitSimplex,double>>.Remove'
'GaTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll', Symbols loaded.

Answer 1

Short answer: http://referencesource.microsoft.com/downloadsetup.aspx

Long answer:

Generally PDB Files are just maps between source code and assembly IL code. To make it work you need to have source code downloaded to the location "hardcoded" in PDB. You can find this location just viewing PDB file in text viewer. For instance if you see System.pdb, you will see lines like that:

f:\dd\ndp\fx\src\net\system\net\websockets\websocketconnectionstream.cs f:\dd\ndp\fx\src\services\monitoring\system\diagnosticts\eventloginternal.cs

There are some poorly documented methods to override this behavior, but it's another story. You also need to make sure you have properly configured debug settings in your visual studio: Tools\Options\Debugging\General

You can download source code and detailed instructions from here.