build BUGFIX added path PKG_CONFIG_PATH
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 414b5cb..886b134 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -287,6 +287,8 @@
     # check that pkg-config includes the used path
     execute_process(COMMAND ${PKG_CONFIG_EXECUTABLE} --variable pc_path pkg-config RESULT_VARIABLE RETURN OUTPUT_VARIABLE PC_PATH ERROR_QUIET)
     if(RETURN EQUAL 0)
+	string(STRIP "${PC_PATH}" PC_PATH)
+	set(PC_PATH "${PC_PATH}:$ENV{PKG_CONFIG_PATH}")
         string(REGEX MATCH "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}/pkgconfig" SUBSTR "${PC_PATH}")
         string(LENGTH "${SUBSTR}" SUBSTR_LEN)
         if(SUBSTR_LEN EQUAL 0)