why does it still require nvidia thrust cuda after set USE_CUDA to OFF

[lidh15]

when I cmake FedTree without CUDA:

Complie without CUDA
CMake Deprecation Warning at thrust/CMakeLists.txt:9 (cmake_policy):
  The OLD behavior for policy CMP0104 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.

-- Could NOT find libcudacxx (missing: libcudacxx_DIR)
CMake Error at thrust/thrust/cmake/thrust-config.cmake:709 (find_package):
  Could not find a package configuration file provided by "libcudacxx"
  (requested version 1.8.0) with any of the following names:

    libcudacxxConfig.cmake
    libcudacxx-config.cmake

  Add the installation prefix of "libcudacxx" to CMAKE_PREFIX_PATH or set
  "libcudacxx_DIR" to a directory containing one of the above files.  If
  "libcudacxx" provides a separate development package or SDK, be sure it has
  been installed.
Call Stack (most recent call first):
  thrust/cmake/ThrustAddSubdir.cmake:1 (find_package)
  thrust/CMakeLists.txt:59 (include)

-- Configuring incomplete, errors occurred!
make: *** No targets specified and no makefile found.  Stop.

don't we have a CPU only mode?

[lidh15]

okay, my, I forget to checkout submodules' to assigned commit.