Taken from the Debian package.

From 7be4a19b76d98260cf95040a47935f854a4ba7a4 Mon Sep 17 00:00:00 2001
From: Valentin Rusu <kde@rusu.info>
Date: Sat, 17 Dec 2011 13:47:58 +0100
Subject: [PATCH] Fix .pc file by adding clucene-shared library

---
 src/core/libclucene-core.pc.cmake |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/src/core/libclucene-core.pc.cmake
+++ b/src/core/libclucene-core.pc.cmake
@@ -6,6 +6,6 @@ includedir=${prefix}/include:${prefix}/i
 Name: libclucene
 Description: CLucene - a C++ search engine, ported from the popular Apache Lucene
 Version: @CLUCENE_VERSION_MAJOR@.@CLUCENE_VERSION_MINOR@.@CLUCENE_VERSION_REVISION@.@CLUCENE_VERSION_PATCH@
-Libs: -L${prefix}/@LIB_DESTINATION@/ -lclucene-core
+Libs: -L${prefix}/@LIB_DESTINATION@/ -lclucene-core -lclucene-shared
 Cflags: -I${prefix}/include -I${prefix}/include/CLucene/ext
 ~
