> [build on U2 fails phenomenally followed by an almost success]

...well, what looks like an almost success. :-)

> IIRC, you should not be building straight into / if you can help it.

Okay, I tried a build with -d -r -D /altroot -O /usr/obj -U (run as the
non-root user to whom I chowned /altroot and /usr/obj).  This chugged
along for a while and then fell over with

includes ===> gnu/lib/libstdc++
STRIP=/usr/obj/tools/tools.NetBSD-1.6D-sparc64/bin/sparc64--netbsd-strip /usr/obj/tools/tools.NetBSD-1.6D-sparc64/bin/nbinstall -U -M /altroot/METALOG -r -c -o root -g wheel  -m 444 /usr/src/gnu/lib/libstdc++/_G_config.h /altroot/usr/include/g++/_G_config.h
includes ===> gnu/lib/libstdc++/include
/usr/obj/tools/tools.NetBSD-1.6D-sparc64/bin/sparc64--netbsd-c++ -O -ffixed-g4  -mcmodel=medlow  -Werror -nostdinc++ -isystem /altroot/usr/include/g++  -nostdinc -isystem /altroot/usr/include   -o /usr/src/gnu/lib/libstdc++/include/../../../dist/toolchain/libstdc++/valarray /usr/src/gnu/lib/libstdc++/include/../../../dist/toolchain/libstdc++/valarray.cc 
/usr/src/gnu/lib/libstdc++/include/../../../dist/toolchain/libstdc++/valarray.cc:1: std/std_valarray.h: No such file or directory
*** Error code 1

Stop.
nbmake: stopped in /usr/src/gnu/lib/libstdc++/include

I really kinda wonder what it is with me that I keep running into
trouble that it seems nobody else is....

/~\ The ASCII				der Mouse
\ / Ribbon Campaign
 X  Against HTML	       mouse@rodents.montreal.qc.ca
/ \ Email!	     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B