I think it's the file called "nw". Sorry I haven't really looked at the Linux build much, I don't have a machine that runs it. I didn't know if renaming anything would cause issues.
The file "nw" isn't an executable it's a shared library.
You have to mark "nw" as an executable ('chmod +xxx nw' in the terminal) and install some external libraries 'libatomic'. I did this and works for me
