[Hezron]

I stuck at step 6 and a complete linux newb using mint.
When I try to use the Makefile command I get the following error code:

cc -c -o build/main.o src/main.c -O2 -Wall -Wno-strict-aliasing
In file included from src/connection.h:5:0,
                 from src/main.c:2:
src/netcode.h:10:10: fatal error: errno.h: No such file or directory
 #include <errno.h>
          ^~~~~~~~~
compilation terminated.
Makefile:30: recipe for target 'build/main.o' failed
make: *** [build/main.o] Error 1

I don't know where to go from here?