I am using the (as of now) latest version of ImGui, https://github.com/ocornut/imgui/blob/79e18896fee8c28f6dae0750b1e808c1b27d7807/imgui.h#L95 Format warning are **not** enabled for GCC on Linux. I was reading https://github.com/ocornut/imgui/issues/3592 and I believe excluding gcc was an unintentional side effect?