I have two VS 2008 solutions I'm working with. One is a web app calling components built in the other solution. Is it possible to somehow start a debugging session in the web solution and have it hit breakpoints in the second solution (cue laugh track)?
I'd prefer not to have to add the various component projects to the web solution in order to debug them, but that may well turn out to be the case. Thought I'd ask if there was another way just the same. Thanks.
Not unless the two components are in the same process, no. There is one or zero debugged process per debugger, and exactly one attached debugger per debugged process.
Depending on what you intend, placing hard-code DebugBreak() in your code might allow you to trigger a second instance of the debugger. In this way your client code can trigger breakpoints in the back-end. Sometimes this method is more convenient than simply attaching the debugger to the server process and setting breakpoints via the IDE.
In any case, if you have two processes to debug, you must use two instances of the debugger, not one.
To augment what Dani mentioned, go to your Project's properties and click on Debug. From there you can start an external program (another VS instance). This will launch VS as part of the debug process.
You can add one solution to another - maybe this will give you what you want but keep your two solutions isolated to a degree: