Only in mariadb-connector-c-2.1.0-src-patched: build
diff -ru mariadb-connector-c-2.1.0-src/cmake/install.cmake mariadb-connector-c-2.1.0-src-patched/cmake/install.cmake
--- mariadb-connector-c-2.1.0-src/cmake/install.cmake	2015-01-29 19:21:48.000000000 +0100
+++ mariadb-connector-c-2.1.0-src-patched/cmake/install.cmake	2015-06-15 10:13:20.606866327 +0200
@@ -116,10 +116,14 @@

 IF(NOT PREFIX_INSTALL_DIR)
   SET(PREFIX_INSTALL_DIR_${INSTALL_LAYOUT} ${libmariadb_prefix})
+ELSE()
+  SET(PREFIX_INSTALL_DIR_${INSTALL_LAYOUT} ${PREFIX_INSTALL_DIR})
 ENDIF()

 IF(NOT SUFFIX_INSTALL_DIR)
   SET(SUFFIX_INSTALL_DIR_${INSTALL_LAYOUT} "mariadb")
+ELSE()
+  SET(SUFFIX_INSTALL_DIR_${INSTALL_LAYOUT} ${SUFFIX_INSTALL_DIR})
 ENDIF()

 FOREACH(dir "BIN" "LIB" "INCLUDE" "DOCS" "PREFIX" "SUFFIX" "PLUGIN")
diff -ru mariadb-connector-c-2.1.0-src/libmariadb/CMakeLists.txt mariadb-connector-c-2.1.0-src-patched/libmariadb/CMakeLists.txt
--- mariadb-connector-c-2.1.0-src/libmariadb/CMakeLists.txt	2015-01-29 19:21:48.000000000 +0100
+++ mariadb-connector-c-2.1.0-src-patched/libmariadb/CMakeLists.txt	2015-06-15 10:14:22.327383479 +0200
@@ -435,7 +435,7 @@
                 "${CMAKE_BINARY_DIR}/libmariadb/libmysqlclient${CMAKE_SHARED_LIBRARY_SUFFIX}"
                 "${CMAKE_BINARY_DIR}/libmariadb/libmysqlclient_r${CMAKE_SHARED_LIBRARY_SUFFIX}"
                 "${CMAKE_BINARY_DIR}/libmariadb/libmysqlclient${CMAKE_STATIC_LIBRARY_SUFFIX}"
-                DESTINATION ${LIB_INSTALL_DIR}/mariadb)
+                DESTINATION ${LIB_INSTALL_DIR}/${SUFFIX_INSTALL_DIR})
 ENDIF()

 INSTALL(DIRECTORY ${CMAKE_SOURCE_DIR}/include/