Thanks Giovanni,
Now no problem with the command line builds.
Nevertheless I don't really how to achieve the same thing in eclipse. I still had had all the includes not referenced. I found that by first clicking
"clean project" this would make eclispe to find the includes

. By the way, when I click
"clean project" it looks like the process finishes by a normal ans successful build. If right after I click "build project", it's going to say
"make: Nothing to be done for `all'.". Then I try to modify the code and launch another build. It still says
"make: Nothing to be done for `all'.".
Lastly if I modify the code with a big mistake or something missing and then click "clean project" it will perform like everything was fine.
Given these little tests I don't understand how to use
eclipse the modify rebuild test ...