Gary Parker writes:
| './build.sh tools' ran quite happily although I was confused to see that it
| produced '/usr/src/tooldir.NetBSD-2.0_RC5-sparc' even though I'd checked out
| the 2.0 release branch from CVS.

This probably means that you did the build with a 2.0_RC5 kernel running.
After rebooting with the newly compiled 2.0 kernel, the build script will
by default look for tools in a 2.0 directory. So by default you have to
remake new tools for the rest to work correctly.
You can change the default tooldir with the -T option or the TOOLDIR
variable.

It's true that it's a little bit confusing in the beginning. I don't know
if this can be improved easily but error messages when tools are not
found are not really clear, sometimes.