i found it is useless and cdbs is setting up prefix automatically.

SVN revision: 39695

diff --git a/debian/rules b/debian/rules
index d26c3f9..6acb8ff 100755 (executable)
--- a/debian/rules
+++ b/debian/rules
@@ -3,7 +3,7 @@
 include /usr/share/cdbs/1/rules/debhelper.mk
 include /usr/share/cdbs/1/class/autotools.mk
 
-DEB_CONFIGURE_SCRIPT := ./autogen.sh --prefix=/usr
+DEB_CONFIGURE_SCRIPT := ./autogen.sh
 DEB_MAKE_CLEAN_TARGET := distclean
 DEB_CONFIGURE_EXTRA_FLAGS := --disable-rpath