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

请将Makefile里面的
-L/usr/lib/mysql
改为
-L/usr/lib64/mysql 

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或者:
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# cd /usr/lib
# mv lib lib.bak
# ln -s /usr/lib64/mysql /usr/lib/mysql