ImAxes | Immersive visualisation tool for multidimensional data | Augmented Reality library

Yes. The way to do it is to follow the second rule of makefiles.

Your rules say you will build a file such as gtk-connection.o. But what the recipes in your rules actually do is build a file such as main/classification/gtk-connection.o. You are not telling the truth to make, so the next time you run make it looks to see if the file gtk-connection.o exists, and it never does, so make always decides to rebuild it.

You need to either change the target of your rule to reflect the actual file you want to be built, or you have to change your recipe to build the file you told make you would build.

In general you really should try to take advantage of make's features for simplifying makefiles such as pattern rules, automatic variables, etc.