我是自己编译安装的，每次用都yaourt命令都出现
==> WARNING: problem in pkgbuild.sh library
Unable to open file: /usr/local/etc/pacman.conf
Unable to open file: /usr/local/etc/pacman.conf
这是pacman -v的结果
Root : /
Conf File : /etc/pacman.conf
DB Path : /var/lib/pacman/
Cache Dirs: /var/cache/pacman/pkg/
Lock File : /var/lib/pacman/db.lck
Log File : /var/log/pacman.log
GPG Dir : /etc/pacman.d/gnupg/
Targets : 无
错误：没有指定的操作 (使用 -h 获取帮助）
我试着复制pacman.conf到/usr/local/etc/ 警告变成了：
==> WARNING: problem in pkgbuild.sh library
failed to initialize alpm library (could not find or read directory)
failed to initialize alpm library (could not find or read directory)
failed to initialize alpm library (could not find or read directory)
怎么回事呢，新手表示不懂。。。

请具体说明你是怎么“编译安装”的。
初步猜测是安装时prefix指定到/usr/local去了。