title: tensorflow 1.13.1 doesn't detect gpu
body: <p>I have been struggling with this for a while and read all the posts I found. I have gtx 1080 gpu on Ubuntu 16.04. My requirement is tensorflow 1.13.1. In my conda env I l have</p>
  
  <pre><code>_libgcc_mutex             0.1                        main  
  _tflow_select             2.1.0                       gpu  
  absl-py                   0.7.1                    py36_0    conda-forge
  astor                     0.7.1                      py_0    conda-forge
  c-ares                    1.15.0            h516909a_1001    conda-forge
  ca-certificates           2019.6.16            hecc5488_0    conda-forge
  certifi                   2019.6.16                py36_1    conda-forge
  cudatoolkit               10.0.130                      0  
  cudnn                     7.6.0                cuda10.0_0  
  gast                      0.2.2                      py_0    conda-forge
  grpcio                    1.16.1           py36hf8bcb03_1  
  h5py                      2.9.0           nompi_py36hf008753_1102    conda-forge
  hdf5                      1.10.4          nompi_h3c11f04_1106    conda-forge
  keras-applications        1.0.7                      py_1    conda-forge
  keras-preprocessing       1.0.9                      py_1    conda-forge
  libblas                   3.8.0               10_openblas    conda-forge
  libcblas                  3.8.0               10_openblas    conda-forge
  libffi                    3.2.1             he1b5a44_1006    conda-forge
  libgcc-ng                 9.1.0                hdf63c60_0  
  libgfortran-ng            7.3.0                hdf63c60_0  
  liblapack                 3.8.0               10_openblas    conda-forge
  libopenblas               0.3.6                h6e990d7_5    conda-forge
  libprotobuf               3.9.0                h8b12597_0    conda-forge
  libstdcxx-ng              9.1.0                hdf63c60_0  
  markdown                  3.1.1                      py_0    conda-forge
  mock                      3.0.5                    py36_0    conda-forge
  ncurses                   6.1               hf484d3e_1002    conda-forge
  numpy                     1.16.4           py36h95a1406_0    conda-forge
  openblas                  0.3.6                h6e990d7_5    conda-forge
  openssl                   1.1.1c               h516909a_0    conda-forge
  pip                       19.2.1                   py36_0    conda-forge
  protobuf                  3.9.0            py36he1b5a44_0    conda-forge
  python                    3.6.7             h357f687_1005    conda-forge
  readline                  8.0                  hf8c457e_0    conda-forge
  scipy                     1.3.0            py36h921218d_0    conda-forge
  setuptools                41.0.1                   py36_0    conda-forge
  six                       1.12.0                py36_1000    conda-forge
  sqlite                    3.29.0               hcee41ef_0    conda-forge
  tensorboard               1.13.1                   py36_0    conda-forge
  tensorflow                1.13.1                   py36_0    conda-forge
  tensorflow-estimator      1.13.0                     py_0  
  tensorflow-gpu            1.13.1               h0d30ee6_0  
  termcolor                 1.1.0                      py_2    conda-forge
  tk                        8.6.9             hed695b0_1002    conda-forge
  werkzeug                  0.15.5                     py_0    conda-forge
  wheel                     0.33.4                   py36_0    conda-forge
  xz                        5.2.4             h14c3975_1001    conda-forge
  zlib                      1.2.11            h516909a_1005    conda-forge
  </code></pre>
  
  <p>AFAIK, all the required software is there and are the right versions, cudnn, cuda-toolkit, tensorflow-gpu. But still tensorflow does not detect gpu. device_lib.list_local_devices() only reports CPU. </p>
  
  <p>Anyone can suggest what else can be wrong?</p>