I'm not sure to understand your hypothesis. I compiled the project starting without a .dbg file. The compiler generate the .dbg file, but the linker don't find it, reporting a path truncated in the space position. With respect to my intial post, the created .dbg file has the following path:
/home/simone/Scrivania/MyGraphEditor 346/mygrapheditor.dbg
The linker says:
/usr/bin/objcopy: "346/mygrapheditor.dbg"": This file does not exist
So I thought that the problem was the space in path. Indeed, if I remove it, the linker works well.