Building trunk -- error msg instrucitons not quite agree with behaviour

["Atwood, Robert C" <r dot atwood at imperial dot ac dot uk>]

I just tried to reconfigure a build so as to change program suffix and
install directory. The build fails but the message reports actions to
take , however these actions do not solve the problem. Only rebuilding
in completely fresh empty directory seems to work. 

  545  make bootstrap
  546  make clean
  547  make distclean
  548  rm -f ./config.cache
  549  ls 
  550  ../gcc-4.3.trunk/configure
--prefix=/usr/local/encap/gccdev-4.4.0.1 --program-suffix=v44
--enable-languages=c,c++,fortran 
  551  make bootstrap 


It told me to :

 run `make distclean' and/or `rm ./config.cache' and start over

So, this instruction seems insufficient to enable the rebuild. 
 
Startign over completely from scratch probably works (i'll find out in a
couple of hours) 




... 

configure: loading cache ./config.cache
configure: error: `CC' has changed since the previous run:
configure:   former value:  /sources/gcc/build-4.3.trunk/./gcc/xgcc
-B/sources/gcc/build-4.3.trunk/./gcc/
-B/usr/local/encap/gcc-4.3.0.1/x86_64-unknown-linux-gnu/bin/
-B/usr/local/encap/gcc-4.3.0.1/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/local/encap/gcc-4.3.0.1/x86_64-unknown-linux-gnu/include -isystem
/usr/local/encap/gcc-4.3.0.1/x86_64-unknown-linux-gnu/sys-include
configure:   current value: /sources/gcc/build-4.3.trunk/./gcc/xgcc
-B/sources/gcc/build-4.3.trunk/./gcc/
-B/usr/local/encap/gccdev-4.4.0.1/x86_64-unknown-linux-gnu/bin/
-B/usr/local/encap/gccdev-4.4.0.1/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/local/encap/gccdev-4.4.0.1/x86_64-unknown-linux-gnu/include
-isystem
/usr/local/encap/gccdev-4.4.0.1/x86_64-unknown-linux-gnu/sys-include
configure: error: changes in the environment can compromise the build
configure: error: run `make distclean' and/or `rm ./config.cache' and
start over
make[1]: *** [configure-fixincludes] Error 1
make[1]: Leaving directory `/sources/gcc/build-4.3.trunk'