Today, after studying for a CS exam for four hours straight, I decided that it would be a good judgment call to write some code. After all, there’s only so much theory one can absorb until code calls. So, I decided to write my first (official) demo. I’m still working on it, and want to compose my own music to it (and make it suck a little less), so it’ll be released later.

I ran into a fun snag along the way, though. I used the SDL libraries to power the graphics of the demo. One library, SDL_Gfx, is not distributed precompiled – you have to compile it yourself. Fortunately, the author includes a Visual C++ Project file that builds just fine. Now, I’ve done some SDL work in the past and had built SDL_Gfx a while ago.

At this point, some readers might see where this is going. As I put some of the hacking finishing touches on the demo, I sent it out to a couple of friends. Of course, it didn’t run on either machine. One was Windows 7, one was Windows XP, and both failed with the same error: The application was unable to start correctly (0x0150002).

A little digging, and the problem pointed to a few solutions – reinstall Windows (yuck), install Visual C++ Express 2008 (double-yuck), or redistribute the debug DLL for Visual C++ 2008 (triple-yuck). This seemed odd to me; I had compiled the demo as a release, non-debug Windows EXE. Why on earth would it need the debug runtime?

Further digging in the event log brought us this error: "Activation context generation failed for "c:\…\release\SDLGFX.DLL". Dependent Assembly Microsoft.VC90.DebugCRT, processorArchitecture="x86", publicKeyToken="1fc8b3b9a1e18e3b", type="win32", version="9.0.21022.8" could not be found. Please use sxstrace.exe for detailed diagnosis."

After a couple of hours of fiddling with manifest files, swearing at SxS, and no luck with the various builds, I stared at the path above. SDLGFX.dll. Then it hit me.

I had built SDL_Gfx as a Debug library in Visual C++ 2008. Crap.

Some swearing and frantic coding later, it works, and runs on other machines. The moral of the story? Always check to make sure your library build type matches your solution type.

I just wish I could have that two hours of my life back.