Debug somebody else's project [here].
The assignment was the following: "implement a function,
print_half_00, that prints half the [0,0] element of a
given gsl_matrix".
You shouldn't rewrite the code, you should only correct the errors—if any—in the Makefile and the code.
The answer to this exercise should be the coorectly built project with
the correct Makefile and the correct main.c
(it's only few lines each).
Hint: you might want to read man 3 printf and find out
what it returns.