I'm running a Fortran program under GDB and GDB complains that the Dwarf version in several GCC6 libraries is 4 and should be 2. I had the same problem with my program and fixed (?) it by compiling with -gdwarf-2, but I can't do that with the GCC libraries. I'm wondering if I should somehow update GDB to be consistent with GCC6 and Dwarf version 4. The GDB version is 6.1.1.