I'm trying to step into an unmanaged C++ dll from a C# application.
They're in the same solution, and the C# app is referencing the DLL
using [DllImport] attributes.  Here's what I've done so far:

1) RTFA.
2) Enabled "Enable unmanaged code debugging" in the C# app's
properties.
3) Set the output path of the DLL to the same as the C# app's output
path.
4) Set the C++ DLL to generate debugging information.  I've also
confirmed that the PDB file does appear in the output folder.
5) Set the C++ DLL's "Debuggable Assembly" attribute to "Runtime
tracking and disable optimizations"
6) Confirmed in the "Modules" window that the DLL was loaded, and that
symbols are present for it.
7) Compiled in "Debug" mode, obviously, and confirmed through
OutputDebugString calls that the DLL code is actually executing.

But I can't step into the DLL's method.  What am I missing?