Thanks!
I have done all the installs using pip, rather than conda. I understood it was possible to do all with pip, (maybe I am wrong), and my feeling is that it is better to use a single system so as to keep everything consistent.
Here is the output of pip freeze:
$ pip3 freeze
certifi==2017.4.17
contextlib2==0.5.5
cracklib==2.9.6
Cython==0.25.2
decorator==4.3.0
docutils==0.13.1
file-magic==0.3.0
gdbus-codegen==2.52.3
gentoolkit==0.4.0
gpg==1.10.0
graphviz==0.8.3
meld==3.18.0
meson==0.45.1
networkx==2.1
numpy==1.10.4
Pillow==5.1.0
portage==2.3.24
pyblake2==1.1.0
pycairo==1.16.3
pycryptsetup==1.7.5
pyelftools==0.24
Pygments==2.2.0
pygobject==3.24.1
pyparsing==2.2.0
pyro-ppl==0.2.0
pyxattr==0.5.5
six==1.11.0
torch==0.4.0
torchvision==0.2.1