Your build was configured with --with-system-db, so plugins/kdb/db2/libdb2 
was not built, and <db.h> was taken from /usr/local/include or the system 
include path.  If that system header does not defined BTREEINFO or 
HASHINFO, then the failure you observed is unsurprising.  Those symbols 
are a documented part of the BDB interface at least as of 4.2.