Ensure protocol buffer prerequisites are present

Builds/CMake/deps/Protobuf.cmake

@@ -9,9 +9,21 @@ if (static)
   set (Protobuf_USE_STATIC_LIBS ON)
 endif ()
 find_package (Protobuf 3.8)
-if (local_protobuf OR NOT Protobuf_FOUND)
+if (is_multiconfig)
+    set(protobuf_protoc_lib ${Protobuf_PROTOC_LIBRARIES})
+else ()
+    string(TOUPPER ${CMAKE_BUILD_TYPE} upper_cmake_build_type)
+    set(protobuf_protoc_lib ${Protobuf_PROTOC_LIBRARY_${upper_cmake_build_type}})
+endif ()
+if (local_protobuf OR NOT (Protobuf_FOUND AND Protobuf_PROTOC_EXECUTABLE AND protobuf_protoc_lib))
   include (GNUInstallDirs)
   message (STATUS "using local protobuf build.")
+  set(protobuf_reqs Protobuf_PROTOC_EXECUTABLE protobuf_protoc_lib)
+  foreach(lib ${protobuf_reqs})
+    if(NOT ${lib})
+      message(STATUS "Couldn't find ${lib}")
+    endif()
+  endforeach()
   if (WIN32)
     # protobuf prepends lib even on windows
     set (pbuf_lib_pre "lib")

Builds/containers/packaging/dpkg/debian/control

@@ -17,5 +17,5 @@ Section: devel
 Recommends: rippled (= ${binary:Version})
 Architecture: any
 Multi-Arch: same
-Depends: ${misc:Depends}, ${shlibs:Depends}, libprotobuf-dev
+Depends: ${misc:Depends}, ${shlibs:Depends}, libprotobuf-dev, libprotoc-dev, protobuf-compiler
 Description: development files for applications using xrpl core library (serialize + sign)