Created attachment 409652 [details]
Stack trace at point where evaluation doesn't work

User-Agent:       Mozilla/5.0 (X11; U; Linux x86_64; en-US) AppleWebKit/534.16 SUSE/10.0.633.0 (KHTML, like Gecko) Chrome/10.0.633.0 Safari/534.16

When trying to debug the Diff process within MonoDevelop using the soft debugger then the Diff.CreateDiffs() method then any variable created within the method evaluate as "Unknown identifier".

The values in the Locals window imply that the issue is because of naming and generics, but debugging other generic methods works fine (e.g. the GetDiff method preceding it, which also returns IEnumerable and is generic based on the values passed in). Possibly an issue with nesting generic calls?

Reproducible: Always

Steps to Reproduce:
1. Put breakpoint in the Diff.CreateDiffs() method (around line 217)
2. Run a debug session with the soft debugger that triggers diff creation (e.g. unit tests from https://github.com/IBBoard/monodevelop/tree/Bug664668-HunkCountIssues)
3. Hover mouse over "lineA" or "lineB" or any other value within the method
Actual Results:  
Red text in quick evaluation box showing "Unknown identifier: [name of variable]"

Expected Results:  
Quick evaluation box showing the value of the variable

Used f97a3cc as a base, because of Bug 666380.