Well, debugging in c::b seems to work fine with gdb and simulavr. For your information, I have the following debugger settings:
Debugger initialization commands
target remote localhost:1212
load
break main
continue
You must also select/check the "Do *not* run the debugee" option
Simulavr must already be running in gdbserver mode. i.e. open a dos box and run
before debugging.
I haven't fully tested it by any means, but I can debug avr code that has multiple libraries linked in, so quite a complex hello world example for the debugger. Debugger options are application-wide, not project-wide, so you'll only have to do those settings once.