Help starting a server on Linux

[mal]

So I'm trying to host a server on a Raspberry Pi following this tutorial. 
Everything is going fine until I am asked to enter this:

[SELECT ALL] Code:

sudo make server_install

I am greeted with the error below.

I'm totally new to using Linux so please forgive my ignorance on the subject, I'm simply following a tutorial. I've Googled it and found some similar issues, but have been unable to follow them.
Thank you. (and sorry for the 2 consecutive posts)