[apologies for the lack of threading and proper quoting - I'm not 
currently subscribed to this list, and should have asked for CCs]

 > > This machine is running NetBSD 2.0_RC5.
> How old are the X11 binaries? We linked all X11 libraries with "libpthread"
> unconditonally for some time. If your system has X11 libraries with
> this problem it might explain your Mesa problems.

The X11 binaries are from a similar vintage, IIRC.

There do not appear to be any libraries in /usr/X11R6/lib which are 
linked against libpthread.

> > It shouldn't be the latter, because I ran pkg_chk -r before building
> > anything. So, unless there's a PKGREVISION bump missing somewhere...

 > Did you have old binaries packages on the box? "pkg_chk" might
 > accidently install old binary packages (see PR pkg/32790 for details).

pkg_chk -rn reports nothing which is now out of date, so I think it's 
safe to say that old binary packages haven't been installed.

-- 
Gillette - the best a man can forget