Add documentation for debugging Godot Engine with CLion (#4376)

Co-authored-by: Gwendhal CLAUDEL <[email protected]>
Co-authored-by: Hugo Locurcio <[email protected]>

development/cpp/configuring_an_ide/clion.rst

@@ -42,3 +42,30 @@ which can also be used by CLion.
 
 If you run into any issues, ask for help in one of
 `Godot's community channels <https://godotengine.org/community>`__.
+
+Debugging the project
+---------------------
+
+Since CLion does not support SCons, you won't be able to compile, launch, and debug Godot from CLion in one step.
+You will first need to `compile godot yourself <https://docs.godotengine.org/en/stable/development/compiling/index.html>`__ and run the binary without CLion. You will then be able to debug Godot by using the `Attach to process <https://www.jetbrains.com/help/clion/attaching-to-local-process.html>`__ feature.
+
+- Run the compilation in debug mode by entering ``scons``.
+
+- Run the binary you have created (in the bin directory). If you want to debug a specific project, run the binary with the following arguments : ``--editor --path path/to/your/godot/project``. To run the project instead of editing it, remove the ``--editor`` argument.
+
+- In CLion, go to **Run > Attach to Process...**
+
+.. figure:: img/clion_4_select_attach_to_process.png
+   :align: center
+
+- Find and Select godot in the list (or type the binary name/Process ID)
+
+.. figure:: img/clion_5_select_godot_process.png
+   :align: center
+
+You can now use the debugging tools from CLion.
+
+.. note::
+
+    If you run the binary without any arguments, you will only debug the project manager window.
+    Don't forget to add the ``--path path/to/your/godot/project`` argument to debug a project.