On Wed, Aug 06, 2003 at 08:09:21PM +0100, David Laight wrote:
  | > Unfortunately that blows up somewhere trying to build groff
  | 
  | Delete the tools directory from the object tree.
  | 
  | The default of having the kernel version in the directory name doesn't
  | work for update builds.  If you force a fixed directory (with -T)
  | then update builds seem to work.

It should now I've added the "PREVIOUSTOOLDIR" support in tools/Makefile.
In fact, I tested that scenario (update builds, TOOLDIR changed).