cppunit默認安裝目錄是/usr/local，執行autoreconf -if會報錯warning: macro `AM_PATH_CPPUNIT' not found in library
cppunit.m4默認在/usr/local/share/aclocal目錄下，但aclocal在/usr/share/aclocal-$VERSION和/usr/share/aclocal兩個目錄下尋找，aclocal認為cppunit配置安裝時使用--prefix=/usr指定了/usr目錄，實際上默認是/usr/local/
解決方法：
1.設置ACLOCAL
ACLOCAL="aclocal -I /usr/local/share/aclocal" autoreconf -if
2.設置ACLOCAL_PATH
ACLOCAL_PATH=/usr/local/share/aclocal autoreconf -if
3.設置ACLOCAL_FLAGS
ACLOCAL_FLAGS="-I /usr/local/share/aclocal" autoreconf -if
早先版本的autoreconf不太遵循ACLOCAL_PATH或ACLOCAL_FLAGS，使用ACLOCAL是解決問題的最佳方法。
ref：https://issues.apache.org/jira/browse/ZOOKEEPER-1454