http://goodies.xfce.org/提供了许多Xfce环境下的插件，其中有个电池监视器插件，按照安装说明中的步骤编译时出现如下错误：
In file included from ./libapm.h:21,
from battery.c:39:
/usr/include/sys/types.h:62: error: conflicting types for 'dev_t'
/usr/include/linux/types.h:19: error: previous declaration of 'dev_t' was here
/usr/include/sys/types.h:67: error: conflicting types for 'gid_t'
/usr/include/linux/types.h:53: error: previous declaration of 'gid_t' was here
/usr/include/sys/types.h:72: error: conflicting types for 'mode_t'
/usr/include/linux/types.h:21: error: previous declaration of 'mode_t' was here
/usr/include/sys/types.h:77: error: conflicting types for 'nlink_t'
/usr/include/linux/types.h:22: error: previous declaration of 'nlink_t' was here
/usr/include/sys/types.h:82: error: conflicting types for 'uid_t'
/usr/include/linux/types.h:52: error: previous declaration of 'uid_t' was here
In file included from /usr/include/sys/types.h:133,
from ./libapm.h:21,
from battery.c:39:
/usr/include/time.h:105: error: conflicting types for 'timer_t'
/usr/include/linux/types.h:28: error: previous declaration of 'timer_t' was here
In file included from /usr/include/sys/types.h:220,
from ./libapm.h:21,
from battery.c:39:
/usr/include/sys/select.h:78: error: conflicting types for 'fd_set'
/usr/include/linux/types.h:18: error: previous declaration of 'fd_set' was here
In file included from ./libapm.h:21,
from battery.c:39:
/usr/include/sys/types.h:235: error: conflicting types for 'blkcnt_t'
/usr/include/linux/types.h:151: error: previous declaration of 'blkcnt_t' was here
make[2]: *** [xfce4_battery_plugin-battery.o] Error 1
make[2]: Leaving directory `/tmp/xfce4-battery-plugin-0.5.1/panel-plugin'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/xfce4-battery-plugin-0.5.1'
from battery.c:39:
/usr/include/sys/types.h:62: error: conflicting types for 'dev_t'
/usr/include/linux/types.h:19: error: previous declaration of 'dev_t' was here
/usr/include/sys/types.h:67: error: conflicting types for 'gid_t'
/usr/include/linux/types.h:53: error: previous declaration of 'gid_t' was here
/usr/include/sys/types.h:72: error: conflicting types for 'mode_t'
/usr/include/linux/types.h:21: error: previous declaration of 'mode_t' was here
/usr/include/sys/types.h:77: error: conflicting types for 'nlink_t'
/usr/include/linux/types.h:22: error: previous declaration of 'nlink_t' was here
/usr/include/sys/types.h:82: error: conflicting types for 'uid_t'
/usr/include/linux/types.h:52: error: previous declaration of 'uid_t' was here
In file included from /usr/include/sys/types.h:133,
from ./libapm.h:21,
from battery.c:39:
/usr/include/time.h:105: error: conflicting types for 'timer_t'
/usr/include/linux/types.h:28: error: previous declaration of 'timer_t' was here
In file included from /usr/include/sys/types.h:220,
from ./libapm.h:21,
from battery.c:39:
/usr/include/sys/select.h:78: error: conflicting types for 'fd_set'
/usr/include/linux/types.h:18: error: previous declaration of 'fd_set' was here
In file included from ./libapm.h:21,
from battery.c:39:
/usr/include/sys/types.h:235: error: conflicting types for 'blkcnt_t'
/usr/include/linux/types.h:151: error: previous declaration of 'blkcnt_t' was here
make[2]: *** [xfce4_battery_plugin-battery.o] Error 1
make[2]: Leaving directory `/tmp/xfce4-battery-plugin-0.5.1/panel-plugin'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp/xfce4-battery-plugin-0.5.1'
make: *** [all] Error 2
解决方法：
打开panel-plugin/libapm.h
将如下两行的位置互换
#include <linux/apm_bios.h>
#include <sys/types.h>
变成
#include <sys/types.h>
#include <linux/apm_bios.h>
重新编译，通过！
