In Makefile xmlibs and sqllibs is defined like this. 
xmllibs := -lxml2 -lz
sqllibs := -lmysql
But this is not correct sometimes.
Actually sqllibs for my environment should be -L'/usr/lib/mysql' -lmysqlclient

If you use the same way as rootlibs. It may be better.

xmllibs := $(shell xml2-config --libs)
xmlcflags := $(shell xml2-config --cflags)
sqllibs := $(shell mysql_config --libs)
sqlcflags := $(shell mysql_config --cflags)