No problem, let me sum it up my issues
I have solved the activation of conda environment problem by using
unset PYTHONPATH
unset PYTHONHOME
Now, the conda environment is activated. Now, when I run
python setup.py install --user as directed from the source,
I am getting
Building wheel torch-1.4.0a0+c63e15a
-- Building version 1.4.0a0+c63e15a
cmake --build . --target install --config Release -- -j 16
/nethome/rxs1576/anaconda3/bin/ninja: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.18' not found (required by /nethome/rxs1576/anaconda3/bin/ninja)
/nethome/rxs1576/anaconda3/bin/ninja: /usr/lib64/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /nethome/rxs1576/anaconda3/bin/ninja)
/nethome/rxs1576/anaconda3/bin/ninja: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /nethome/rxs1576/anaconda3/bin/ninja)
Traceback (most recent call last):
  File "setup.py", line 751, in <module>
    build_deps()
  File "setup.py", line 310, in build_deps
    cmake=cmake)
  File "/nethome/rxs1576/pytorch/tools/build_pytorch_libs.py", line 59, in build_caffe2
    cmake.build(my_env)
  File "/nethome/rxs1576/pytorch/tools/setup_helpers/cmake.py", line 334, in build
    self.run(build_args, my_env)
  File "/nethome/rxs1576/pytorch/tools/setup_helpers/cmake.py", line 142, in run
    check_call(command, cwd=self.build_dir, env=env)
  File "/nethome/rxs1576/anaconda3/envs/conda_env/lib/python3.6/subprocess.py", line 291, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['cmake', '--build', '.', '--target', 'install', '--config', 'Release', '--', '-j', '16']' returned non-zero exit status 1.