Build with debug option

[Hiromichi Watari]

I'm trying to build from development 6.0 source with debug option with the following make
error(first of many).

$ ./configure --with-debug
         .
         .
         .
mysql.o: In function `build_completion_hash':
/usr/local/mysql-6.0-build/client/mysql.cc:2516: undefined reference to `_db_enter_'



I did pull in the source tree with dbug directory with dbug_long.h, dbug.c and so on.
Anybody has any idea ?

Thanks,
Hiromichi