I am following the example square_ff at https://wiki.gnuradio.org/index.php/OutOfTreeModules, but was confused by the usage of this $cmake command. I didn't specify anything to cmake while installing it (if I did install cmake by myself). So I just leave everything as default. Besides, in my /usr/local/lib/ directory, I have python2.7/dist-packages and python3.6/dist-packages. So which version of python should I use for this command, and how this cmake command should be issued? I am sorry that I am not familiar with the format of cmake command at all.
Thanks in advance!