[PATCH] libopensync-plugin-synce-0.22 does not configure on gentoo

[ello]

the ./configure fails with

checking for rra_syncmgr_new in -lrra... no
configure: error: Can't find RRA library

• synce-rra-0.10.0 and
• librapi2-0.10.0

are installed

interesting part in config.log is

configure:4453: gcc -o conftest -g -O2   conftest.c -lrra  -lmimedir  >&5
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_set_dword'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_create_key'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `CeRapiInit'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_query_string'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `CeRegCloseKey'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_query_dword'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `CeStartReplication'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_open_key'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `rapi_reg_set_string'
/usr/lib/gcc/i686-pc-linux-gnu/4.1.2/../../../librra.so: undefined reference to `CeRegQueryValueEx'
collect2: ld returned 1 exit status

It works if I add "-lrapi" in the configure-script (manually oder via configure.in and running autogen.sh again)