This message is generating by the GNU make utility when it determines that no compiles, assembles, links, etc., are required. The makefile, when configured correctly, has a set of dependencies. For example, file Main.o is dependent on file Main.c, such that if Main.o either does not exist, or has an earlier date tag than Main.C the GNU make utility will call the GNU compiler to create a new version of Main.0. The above message indicates that the makefile has determined that no compile or link options are required because all dependent files are up-to-date. To test this, delete all the object and executable image files by typing the following:
Now run the make utility again
You should see all the compile and links take place.