not building?

[Mike Stump]

I've been seeing:

         /Volumes/mrs5/net/gcc-darwin/./gcc/xgcc -shared-libgcc -B/ 
Volumes/mrs5/net/gcc-darwin/./gcc -nostdinc++ -L/Volumes/mrs5/net/gcc- 
darwin/i686-apple-darwin9/libstdc++-v3/src -L/Volumes/mrs5/net/gcc- 
darwin/i686-apple-darwin9/libstdc++-v3/src/.libs -B/usr/local/i686- 
apple-darwin9/bin/ -B/usr/local/i686-apple-darwin9/lib/ -isystem /usr/ 
local/i686-apple-darwin9/include -isystem /usr/local/i686-apple- 
darwin9/sys-include -Winvalid-pch -Wno-deprecated -x c++-header -g - 
O2  -I/Volumes/mrs5/net/gcc-darwin/i686-apple-darwin9/libstdc++-v3/ 
include/i686-apple-darwin9 -I/Volumes/mrs5/net/gcc-darwin/i686-apple- 
darwin9/libstdc++-v3/include -I/Volumes/mrs5/net/gcc/libstdc++-v3/ 
libsupc++ -O2 -g /Volumes/mrs5/net/gcc/libstdc++-v3/include/ 
precompiled/extc++.h -o i686-apple-darwin9/bits/extc++.h.gch/O2g.gch
/Volumes/mrs5/net/gcc/libstdc++-v3/include/precompiled/extc++.h: 
43:29: error: ext/enc_filebuf.h: No such file or directory
make[4]: *** [i686-apple-darwin9/bits/extc++.h.gch/O2g.gch] Error 1
make[3]: *** [all-recursive] Error 1
make[2]: *** [all] Error 2
make[1]: *** [all-target-libstdc++-v3] Error 2
make: *** [all] Error 2

for a couple of builds now.  Surely I'm doing something wrong, but  
svn says it is up to date, and I've rm -rf the target libstdcxx build  
directories...  find doesn't find the named file in either the build  
or source tree...