if you dont have SDL2 installed and your run Trine it complains that SDL is missing and exits.
Hmm, that's a bit dumb. I'm 99% sure I found that SDL 1.3, which we don't have as it was very short-lived, is statically linked so I don't know what it's doing here. I'm away from home right now so I can't check until the weekend.
Sorry, I was getting mixed up with Trine 2. Enchanted Edition is statically linked against SDL 2.0.3 but the download includes a useless copy of SDL 1.3. I tried moving all my libSDL2* libraries out to the way but wasn't able to reproduce this. Is it the launcher or the game itself that fails and what is the exact error message?
When I ran the Trine launcher or the game it displayed a dialog box saying that SDL is missing. It didn't list any version info but I did have SDL1 installed already. I installed libsdl2. After that it worked. I just uninstall SDL 2 Trine continues to start. I'm not able to reproduce so it, you can close the bug.
Oh well.