freebsd-ports/net/libproxy/files/patch-utils-CMakeLists.txt

--- utils/CMakeLists.txt~
+++ utils/CMakeLists.txt
@@ -3,4 +3,5 @@ link_directories(${LIBPROXY_LIBRARY_DIRS
 
 add_executable(proxy proxy.c)
 target_link_libraries(proxy libproxy)
+set(CMAKE_C_COMPILER ${CMAKE_CXX_COMPILER})
 install(TARGETS proxy RUNTIME DESTINATION ${BIN_INSTALL_DIR})