forced X/Open mode on HPUX removed. The correct way (that affects not only C but also C++ and linking) would be
forced X/Open mode on HPUX removed. The correct way (that affects not only C but also C++ and linking) would be

CFLAGS="-D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED -D_HPUX_SOURCE"
CXXFLAGS="-D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED -D_HPUX_SOURCE"
LDFLAGS="-lxnet"

but apparently MySQL works without too.

natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,slanterns/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,ollie314/server,flynn1973/mariadb-aix