message: Helpful error message on missing submodule
diff: # Copyright (c) Microsoft Corporation. All rights reserved.
  # Licensed under the Apache 2.0 License.
  +function(check_submodule_not_empty path)
  + file(GLOB submodule_files "${path}/*")
  + list(LENGTH submodule_files number)
  + if(${number} EQUAL 0)
  + message(FATAL_ERROR "Submodule ${path} is empty. You can initialise submodules now with 'git submodule update --recursive --init', or during 'git clone' by passing '--recursive'.")
  + endif()
  +endfunction()
  +
  +# Give an early, helpful message when submodules are missing
  +check_submodule_not_empty(${CCF_DIR}/3rdparty/evercrypt-msr)
  +
  set(MSGPACK_INCLUDE_DIR ${CCF_DIR}/3rdparty/msgpack-c)
  set(default_build_type "RelWithDebInfo")
  @@ -14,12 +25,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
  find_package(Threads REQUIRED)
  -# Azure Pipelines does not support color codes
  -if (DEFINED ENV{BUILD_BUILDNUMBER})
  set(PYTHON python3)
  -else()
  - set(PYTHON unbuffer python3)
  -endif()
  separate_arguments(COVERAGE_FLAGS UNIX_COMMAND "-fprofile-instr-generate -fcoverage-mapping")
  separate_arguments(COVERAGE_LINK UNIX_COMMAND "-fprofile-instr-generate -fcoverage-mapping")
  