As of a week or so ago, I have been unable to build -current on
sparc64 because gdb always fails to link with the following messages.

    nbsd-thread.o: In function `nbsd_thread_fetch_registers':
    nbsd-thread.o(.text+0x7f0): undefined reference to `supply_gregset'
    nbsd-thread.o(.text+0x7f8): undefined reference to `supply_fpregset'
    nbsd-thread.o: In function `nbsd_thread_store_registers':
    nbsd-thread.o(.text+0x91c): undefined reference to `fill_gregset'
    nbsd-thread.o(.text+0x928): undefined reference to `fill_fpregset'
    nbsd-thread.o: In function `nbsd_thread_proc_getregs':
    nbsd-thread.o(.text+0x1b40): undefined reference to `fill_fpregset'
    nbsd-thread.o(.text+0x1b50): undefined reference to `fill_gregset'
    nbsd-thread.o: In function `nbsd_thread_proc_setregs':
    nbsd-thread.o(.text+0x1bf8): undefined reference to `supply_fpregset'
    nbsd-thread.o(.text+0x1c08): undefined reference to `supply_gregset'
    collect2: ld returned 1 exit status

This builds find with the same source tree on i386. I'll keep digging,
but I don't know much about gdb/bfd configuration (yet).

Lloyd