How do I debug .NET 4.6 framework source code in Visual Studio 2017?

Question

Here's what I've tried:

Made a new Console App (.NET Framework) in Visual Studio 2017.

Added the following code:

static void Main(string[] args)
{
    new Dictionary<int, int>().TryGetValue(3, out int x); //I want to step into TryGetValue() (this is just an example)
}

Configured the settings listed here: https://blogs.msdn.microsoft.com/sburke/2008/01/16/configuring-visual-studio-to-debug-net-framework-source-code/

Confirmed symbols are loaded in the Modules window:

mscorlib.dll Symbols loaded. 4.6.1586.0 built by: NETFXREL2

Tried: "Step Into (F11)"

Tried: "Step into Specific" | "System.Collections.Generic.Dictionary.TryGetValue"

Both just step over the line.

I've tried configuring VS using the details here: http://www.symbolsource.org/Public/Home/VisualStudio

Same result, the debugger steps over the line.

I've looked at the answer here: https://stackoverflow.com/a/12432029/297451

But this version doesn't seem to be a security update, and a search for "site:support.microsoft.com/kb 4.6.1586.0" yields nothing.

What am I doing wrong?

Answer 1

Here is the answer, thanks to Hans Passant. Note that this solution raises additional questions.

1. Ensure https://referencesource.microsoft.com/ contains the exact version you're debugging.

   • How? Reference source specifies ".NET Framework 4.6.2" but a module version is something like: "4.6.1586.0"
   • You may need to uninstall security updates as explained here: How do you enable "Enable .NET Framework source stepping"?

2. Configure Visual Studio as specified here: https://referencesource.microsoft.com/setup.html

   • Untick "Enable Just My Code"
   • Tick "Enable .NET Framework source stepping" (this should have been the only step needed)
   • Tick "Enable source server support"
   • Untick "Require source files to exactly match the original version"

3. Confirm symbols are loaded in the Modules window, with source indexing included.

   • How can you tell if source indexing is included? The modules window doesn't specify if a PDB has stripped source information.

Microsoft could make this process a lot more robust by giving helpful error messages instead of silently failing.