Compiling drivers/X11/Fl_X11_System_Driver.cxx...
drivers/X11/Fl_X11_System_Driver.cxx: In member function ‘virtual int Fl_X11_System_Driver::clocale_snprintf(char*, size_t, 

const char*, __va_list_tag*)’:

drivers/X11/Fl_X11_System_Driver.cxx:108:7: warning: unused variable ‘retval’ [-Wunused-variable]
  108 |   int retval = vsnprintf(output, output_size, format, args);
      |       ^~~~~~
drivers/X11/Fl_X11_System_Driver.cxx:116:1: warning: no return statement in function returning non-void [-Wreturn-type]
  116 | }
      | ^
drivers/X11/Fl_X11_System_Driver.cxx: In member function ‘virtual int Fl_X11_System_Driver::clocale_sscanf(const char*, const char*, __va_list_tag*)’:
drivers/X11/Fl_X11_System_Driver.cxx:123:7: warning: unused variable ‘retval’ [-Wunused-variable]
  123 |   int retval = vsscanf(input, format, args);
      |       ^~~~~~
drivers/X11/Fl_X11_System_Driver.cxx:131:1: warning: no return statement in function returning non-void [-Wreturn-type]
  131 | }
      | ^