cmake -B build -DWITH_MULTIPROCESS=ON
<snip>
CMake Warning at CMakeLists.txt:146 (find_package):
  By not providing "FindLibmultiprocess.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "Libmultiprocess", but CMake did not find one.

  Could not find a package configuration file provided by "Libmultiprocess"
  with any of the following names:

    LibmultiprocessConfig.cmake
    libmultiprocess-config.cmake

  Add the installation prefix of "Libmultiprocess" to CMAKE_PREFIX_PATH or
  set "Libmultiprocess_DIR" to a directory containing one of the above files.
  If "Libmultiprocess" provides a separate development package or SDK, be
  sure it has been installed.


-- Could NOT find LibmultiprocessNative (missing: LibmultiprocessNative_DIR)
<snip>
CMake Error at src/ipc/CMakeLists.txt:12 (target_capnp_sources):
  Unknown CMake command "target_capnp_sources".


-- Configuring incomplete, errors occurred!