pgxs may not define FLEX/BISON
pgxs may not define FLEX/BISON

nad2000/plproxy,markokr/plproxy-dev,mpihlak/plproxy-dev,markokr/plproxy-dev,petere/plproxy-dev,saaros/plproxy-dev,myrkraverk/plproxy,saaros/plproxy-dev