尝试构建 memcached 1.6，但失败并出现以下错误。如何解决问题？
libtool：编译：gcc -std=gnu99 -DHAVE_CONFIG_H -I。-I./include -I./libevent -I./engines/default_engine -I./include -I./libevent -fvisibility=hidden -pthread -g -O2 -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-声明 -Wredundant-decls -MT default_engine_la-assoc.lo -MD -MP -MF .deps/default_engine_la-assoc.Tpo -c 引擎/default_engine/assoc.c -fPIC -DPIC -o .libs/default_engine_la-assoc.o mv -f .deps/default_engine_la-assoc.Tpo .deps/default_engine_la-assoc.Plo /bin/sh ./libtool --tag=CC --mode=compile gcc -std=gnu99 -DHAVE_CONFIG_H -I. -I./include -I./libevent -I./engines/default_engine -I./include -I./libevent -fvisibility=hidden -pthread -g -O2 -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-声明 -Wredundant-decls -MT default_engine_la-default_engine.lo -MD -MP -MF .deps/default_engine_la-default_engine。test -f 'engines/default_engine/default_engine.c' || echo './'引擎/default_engine/default_engine.c libtool：编译：gcc -std=gnu99 -DHAVE_CONFIG_H -I。-I./include -I./libevent -I./engines/default_engine -I./include -I./libevent -fvisibility=hidden -pthread -g -O2 -Wall -Werror -pedantic -Wmissing-prototypes -Wmissing-声明 -Wredundant-decls -MT default_engine_la-default_engine.lo -MD -MP -MF .deps/default_engine_la-default_engine.Tpo -c 引擎/default_engine/default_engine.c -fPIC -DPIC -o .libs/default_engine_la-default_engine.o
engine/default_engine/default_engine.c：在函数“initialize_configuration”中：engines/default_engine/default_engine.c:506:22：错误：变量“ret”设置但未使用[-Werror=unused-but-set-variable]
cc1: 所有警告都被视为错误 make[1]: * [default_engine_la-default_engine.lo] 错误 1 make[1]: 离开目录 `/home/user123/Downloads/memcached-1.6.0_beta1' make: * [all]错误 2