Well, you have to pick a compiler. CMake is not a compiler. It's a meta-build system that creates the project files for a specific IDE/compiler/toolchain, so that SFML users can choose which one they want to use.
In terms of not being "tied" to anything or "building raw", the closest you can get to whatever that means is probably setting CMake's generator to "Unix Makefile", which you can simply run "make" on. That doesn't involve any IDE, only the standard Unix toolchain, which I assume you were already using on ArchLinux anyway.
Dunno about that error though. Are you sure there isn't a more descriptive error message somewhere?