VS 2010 debugger not loading symbols when attaching to NUnit

Question

(I just posted this in the NUnit discussion group on groups.google.com)

Under VS 2008, I would run my tests under NUnit, and, if I needed to debug, I would attach the VS2008 debugger to the running Nunit process (Debug -> Attach to Process), and set any breakpoints on code I wanted to examine. When I hit the Run buttion in NUnit, it would hit the breakpoint. (BTW, if it matters, this was running NUnit 2.5.2).

I just upgraded to NUnit 2.5.4 and VS 2010. When I set a breakpoint, then attach to NUnit, I get a little warning symbol on the breakpoint dot, and hovering over it gives the tooltip "Breakpoint will not be hit. No symbols are currently loaded". Going to the Debug -> Windows -> Modules window shows a whole bunch of Windows and NUnit modules loaded, with the Symbol Status of "Skipped loading symbols", and then 1 module with a funny name that changes each time (r1euhmh5 right now), and Symbol Status of "No symbols loaded". (There is no trace of a module with a name remotely like my DLL under test).

Right clicking the funny filename (assuming that to be some mapping from my DLL under test), and clicking Load Symbols From -> Symbol Path, and navigating to the bin\debug folder, then clicking the pdb file of my DLL under test, I get the message "A matching symbol was not found in this folder". (The top of the Open dialog box has a line that says "Original location: r1euhmh5.pdb")

So what's changed? And how do I go about debugging/breakpointing under VS 2010/NUnit 2.5.4 (Or is it possible I screwed something up when I decided to go through my VS2010 options and set some of them to more advanced levels than I knew what I was doing?)

I appreciate any help.

Answer 1

I'm not sure I understand exactly why, but the answer is to attach the debugger to nunit-agent.exe instead of nunit.exe. See Charlie Poole's response here

Answer 2

There's information on this blog post about how to tell NUnit to use the correct .Net framework in the nunit.exe configuration file.

The benefit to fixing this in the configuration file is that it allows you to set up your unit test project so that you can launch NUnit as an external command when you select Debug -> Start New Instance.