mdb_iob_name
mdb_iob_name(mdb.m_in));
mdb_warn("error while reading %s", mdb_iob_name(iob));
mdb_iob_name(mdb.m_in), mdb_iob_name(mdb.m_out));
extern const char *mdb_iob_name(mdb_iob_t *);