When I try to build a system, I'm getting the following error:

Files in DESTDIR but missing from flist.
File is obsolete or flist is out of date ?
------------------------------------------
./etc/pam.d
./usr/bin/c++
./usr/bin/cc
./usr/bin/f77
./usr/bin/g++
./usr/bin/g77
./usr/bin/gcc
./usr/bin/protoize
./usr/bin/unprotoize
./usr/libexec/cc1
./usr/libexec/cc1obj
./usr/libexec/cc1plus
./usr/libexec/f771
=========  end of 13 extra files  ===========

Is anyone else seeing this, or have I made some mistake in my tree?