This is what happened.

me $ sudo apt-get install libsdll.2-dev
blah, blah, blah.

E: Unable to locate package libsdll.2-dev
E: Couldn't find any package by regex 'libsdll.2-dev'

It says it's for the sdl libraries, should I just get libsdl.2-dev instead

I guessed that and installed it though it's nice to know I chose the right thing.

Now, I'm just going to check that I can compile the source for TPT without modding, then I'll change a few things and leave the things that are confusing.

One more thing, "sometimes it adds to the directory the Project name, if that happens, remove the Project name part from the directory"

which directory is this?