Can't build R5 extensions on Linux

[aag]

Trying to run cmake on ./opt/intel/computer_vision_sdk_2018.5.445/deployment_tools/inference_engine/src/extension/CMakeLists.txt. Initially, it fails to find ext_message. Editing the file to 

include(InferenceEngineConfig-version)
include(InferenceEngineConfig)

seems to remediate that particular problem, however, then we're seeing

CMake Error at CMakeLists.txt:30 (add_library):
  add_library cannot create target "ie_cpu_extension" because another target
  with the same name already exists.  The existing target is a shared library
  created in source directory
  "/opt/intel/computer_vision_sdk_2018.5.445/deployment_tools/inference_engine/src/extension".
  See documentation for policy CMP0002 for more details.

CMake Error at /opt/intel/computer_vision_sdk_2018.5.445/deployment_tools/inference_engine/share/ie_parallel.cmake:93 (target_link_libraries):
  Attempt to add link library
  "/opt/intel/computer_vision_sdk_2018.5.445/deployment_tools/inference_engine/external/omp/lib/libiomp5.so"
  to target "ie_cpu_extension" which is not built in this directory.
Call Stack (most recent call first):
  CMakeLists.txt:31 (set_ie_threading_interface_for)

CMake Error at CMakeLists.txt:35 (target_link_libraries):
  Attempt to add link library "IE::inference_engine" to target
  "ie_cpu_extension" which is not built in this directory.

Any advice on that?

[aag]

Seems like Windows fails to build in a similar manner in R5. Is there any documentation on how to build the extensions anywhere?

[nikos1]

Weird - both Linux and Windows version build fine here with R5

What is your cmake, OS/kernel, tools/compiler version?

Also maybe uninstall R4 or previous versions of the SDK just in case.

cheers,

nikos

[nikos1]

What happens if you build extensions as a sub-project of the samples solution ?

i.e. on Windows cmake under C:\Intel\computer_vision_sdk_2018.5.445\inference_engine\samples

[aag]

So, apparently, extensions CMakeLists.txt cannot be as a standalone project. They reference macros from InferenceEngineConfig, which in turn adds extensions subfolder to the build. However, creating a rudimentary top-level CMakeLists.txt

cmake_minimum_required(VERSION 3.9)
include(InferenceEngineConfig)

works fine. 

[Tyagi__Dushyant]

CMAKE_BUILD_TYPE not defined, 'Release' will be used
CMake Error at /opt/intel/computer_vision_sdk/deployment_tools/inference_engine/samples/extension/CMakeLists.txt:27 (add_library):
  add_library cannot create target "ie_cpu_extension" because another target
  with the same name already exists.  The existing target is a shared library
  created in source directory
  "/opt/intel/computer_vision_sdk/deployment_tools/inference_engine/src/extension".
  See documentation for policy CMP0002 for more details.

Trying to use facenet with openVINo but when i run cmake .. then getting above error .

Any advice on that?

[PJIA01]

What is /opt/intel/openvino/deployment_tools/inference_engine/src/extension  about?

And, this extension is NOT able to be built independently?

 CMake Error at CMakeLists.txt:46 (set_ie_threading_interface_for):
   Unknown CMake command "set_ie_threading_interface_for".

How can I have it built then?

Cheers

Pei