Fedora Magazine - https://fedoramagazine.org/debugging-gnome-builder/
GNOME Builder 3.26 ships a number of new features, including improved symbol searching, inline documentation and integrated debugging. Prior to this, developers could code and compile their program in Builder, but would need to switch to a separate debugger (either gdb or a graphical debugger like Nemiver). Now that Builder integrates a debugger, a developer can write, compile and run their program with an attached debugger right inside Builder!
Install GNOME Builder
Builder is available in the main Fedora repositories. Install it with dnf or GNOME Software. If you haven’t yet upgraded to Fedora 27, Builder 3.26 is also available