undefined references on GNU/Hurd

[Alfred M. Szmidt]

On GNU/Hurd with libc from CVS I get this lovely message (and the last
show-stopper for getting into compilable state too!).  This is the
ChangeLog entry that broke it.  Anyone got any ideas?

2003-04-29  Roland McGrath  <roland@redhat.com>

        * include/libc-symbols.h (__symbol_set_attribute): New macro,
        give hidden for [SHARED] and weak for [! SHARED].
        (symbol_set_declare): Use that.  Never need weak_extern these days.

/home/ams/libc-cross-obj/libc_pic.os(.text+0x257b0): In function `__libc_init':
../sysdeps/mach/hurd/set-init.c:23: undefined reference to `__start___libc_subinit'
/home/ams/libc-cross-obj/libc_pic.os(.text+0x257b6):../sysdeps/mach/hurd/set-init.c:23: undefined reference to `__stop___libc_subinit'
collect2: ld returned 1 exit status