I was unable to build an environment for this. The error I got was:
Installing collected packages: steem-piston, diff-match-patch, python-frontmatter, appdirs, colorama, steem, graphenelib, prettytable, PyYAML, asyncio, websockets, ecdsa, txaio, requests, Unidecode, autobahn, scrypt, websocket-client
Running setup.py install for diff-match-patch
Running setup.py install for python-frontmatter
warning: no previously-included files found matching '*.py[co]'
*** Error compiling '/tmp/pip_build_alumno/graphenelib/grapheneapi/graphenewsrpc_BACKUP_13829.py'...
File "/tmp/pip_build_alumno/graphenelib/grapheneapi/graphenewsrpc_BACKUP_13829.py", line 80
<<<<<<< HEAD
^
SyntaxError: invalid syntax
This looks like a problem caused by a merge that didn't go so well. It is in websocket-client. I am not sure how I can help this along. When the error happens the pip3 script clobbers the tmp directories.
Not sure if this will help but try this?
git reset --hard origin
This error results in the easy pip3 method. Any git checkouts were automated and I never modified any source files. I think if I can download graphenelib separately I can find a version that can work, however.
some debian packages mentioned in the graphene install instructions. Then I installed six and graphene manually (ergo: git clone, then setup.py). After that I was able to install piston manually.