64位Linux系统下，源码编译时，有时会无法链接libmysqlclient库：
/usr/bin/ld: skipping incompatible /usr/lib/mysql/libmysqlclient.so when searching for -lmysqlclient
/usr/bin/ld: skipping incompatible /usr/lib/mysql/libmysqlclient.a when searching for -lmysqlclient[......]