deng cmake

The C compiler identification is GNU 9.3.0
The CXX compiler identification is GNU 9.3.0
Check for working C compiler: /usr/bin/cc
Check for working C compiler: /usr/bin/cc -- works
Detecting C compiler ABI info
Detecting C compiler ABI info - done
Detecting C compile features
Detecting C compile features - done
Check for working CXX compiler: /usr/bin/c++
Check for working CXX compiler: /usr/bin/c++ -- works
Detecting CXX compiler ABI info
Detecting CXX compiler ABI info - done
Detecting CXX compile features
Detecting CXX compile features - done
Configuring doomsday...
Install prefix: /usr
QMake path: /usr/bin/qmake
  Qt version: 5.12.8
  Qt install prefix: /usr
Performing Test COMPILER_SUPPORTS_CXX11
Performing Test COMPILER_SUPPORTS_CXX11 - Success
Performing Test COMPILER_SUPPORTS_CXX0X
Performing Test COMPILER_SUPPORTS_CXX0X - Success
Configuring sdk...
Configuring libcore...
Found ZLIB: /usr/lib/x86_64-linux-gnu/libz.so (found version "1.2.11")
Revision: v2.3.0-0-ge7383f81b7
Wrote doomsday/sdk/libcore/net.dengine.stdlib.pack (contains 5 files).
Configuring libshell...
Configuring liblegacy...
CMake Error at doomsday/sdk/libgui/CMakeLists.txt:50 (add_subdirectory):
  The source directory

    /home/stas/doom/dengsrc/doomsday/external/assimp

  does not contain a CMakeLists.txt file.


CMake Error at doomsday/sdk/libgui/CMakeLists.txt:51 (set_property):
  set_property could not find TARGET assimp.  Perhaps it has not yet been
  created.


Configuring libgui...
CMake Error at doomsday/cmake/FindAssimp.cmake:57 (message):
  Open Asset Import Library not found.  Go to
  /home/stas/doom/dengsrc/doomsday/external/assimp and compile.  If you
  install it somewhere, set the ASSIMP_DIR variable to specify the location.
  If pkg-config is available, it is used to find libassimp.
Call Stack (most recent call first):
  doomsday/sdk/libgui/CMakeLists.txt:86 (find_package)


Configuring incomplete, errors occurred!