: this is strange. it occurs only when i build with HOST_CFLAGS="-O2 -g":
   
   On what host $MACHINE_ARCH and OS?  (With the new toolchain, it's not so
   obvious anymore.  :)

this is native; powermac g4 running -current.
   
   Oddly enough, the first error that shows up here comes from a #else block
   that should never get pulled in:
   
   : /usr/src/tools/toolchain/../../gnu/dist/toolchain/gcc/system.h:353: conflicting types for `sys_errlist'
   : /usr/include/errno.h:59: previous declaration of `sys_errlist'
   
   The "sys_errlist" block in system.h is supposed to be used when
   HAVE_STRERROR is not set.  On NetBSD hosts, HAVE_STRERROR should most
   definitely be set....


hmmm.. lemme see...i have HAVE_STRERROR defined in gcc/auto-host.h...
hmmm.. i will investigate more and see.