
The included binary is for linux/x86. If it doesn't work for you, you need
either remove it (and let the install script use 7z from somewhere else
in your PATH; however, it must be at least version 9.20) or compile it
from source.

To compile it from source on OS X:

tar -jxvf p7zip_9.20.1_src_all.tar.bz2
cd p7zip_9.20.1
cp makefile.macosx_64bits makefile.machine
make 7z
cp bin/7z ..
cp bin/7z.so ..

On linux, do the same, just skip copying the makefile.

