I wrote:

> I just did the following, and then it compiles OK (but I haven't
> tested any of the resulting servers, so they very well may not work):
> [...]

Oh, hang on -- I did this under /usr/src, as well:

--- x11/Xserver/Makefile.common 21 Mar 2005 00:49:17 -0000      1.21
+++ x11/Xserver/Makefile.common 30 Mar 2005 20:18:53 -0000
@@ -75,8 +75,8 @@
 .endif
 
 .if ${MACHINE} == "vax"
-XSERVER_HAS_FB=                no
 XSERVER_XVFB=          no
+XSERVER_NEEDS_MIEXT=   yes
 .endif

-tih
-- 
Don't ascribe to stupidity what can be adequately explained by ignorance.