Quick tutorial error "Uundefined symbol: _PyTraceback_Add"

[Yetta]

I am wanting to step through the tutorials but I get
"ImportError: /home/brian/projects/quick_tutorial/env/lib/python3.4/lib-dynload/_ctypes.cpython-34m-x86_64-linux-gnu.so: undefined symbol: _PyTraceback_Add"
I am in this directory
~/projects/quick_tutorial/scaffolds
and I try running
$VENV/bin/python setup.py develop

The ~/projects/quick_tutorial/env/bin   folder does have a copy of python3.4

Any idea what I am missing?
Thanks
Brian

[Steve Piercy]

You mean this?
http://docs.pylonsproject.org/projects/pyramid/en/latest/quick_tutorial/scaffolds.html

Do this:

$VENV/bin/python

What python version shows? If not Python 3.4.x (as you would
expect), then try this:

$VENV/bin/python3

...and if it shows 3.4.x, then adjust any command with 'python'
to use 'python3' instead.

[Note to self, we might need to add a step for users to check
that they have the desired Python version as the default in
their PATH.]

Next, did you do the previous step 2?

$VENV/bin/pcreate --scaffold starter scaffolds

Next, did you follow Requirements previously and to the letter?
http://docs.pylonsproject.org/projects/pyramid/en/latest/quick_tutorial/requirements.html

If you did not, then start over with a clean directory, and
follow every step. Do not go off the beaten path with pip,
unless you know the implications (as stated at the end of Requirements).

--steve


On 8/9/15 at 9:03 PM, brian....@gmail.com (Yetta) pronounced:

------------------------
Steve Piercy, Soquel, CA

[Yetta]

Hi Steve
Thanks for your help. I do get Python 3.4.0 when I run $VENV/bin/python
I also had all of the requirements followed and I executed all steps in the scaffolds.html page. (I used copy/paste so there were no typos etc.
I will take the suggestion of wiping the directory and starting the tutorial again.  I will repost here to let you know what happens

Thanks again.
Brian

fyi (in case it turns out to be interesting...).  I had progressed as far as tutorial 12  (Templating with Jinja2) when I first noticed the error.  It is possible the error occurred before this step and I hadn't noticed it.  In any event, I went back over previous tutorials, eventually going back to the scaffolds tutorial, and the error still came up.  But a clean start will be useful, and as I said, I will post the outcome here.   Cheers.

[Yetta]

Hi Steve (and other readers)
I have worked out what my misunderstanding was and I share it so that others can avoid the (perhaps too obvious) trap I fell in to.
I was not in the new environment when I was running the tutorials.  I had worked through the first 11 tutorials, and then came back to number 12 on the next day (and thus in a new terminal). In looking at your advice to follow Requirements.html  to the letter, I thought I had already done so. But I now realize that my terminal session did not have (env) as part of the prompt.

But all is well now, and I am progressing through the remaining tutorials. 
Thanks for your help Steve. It is nice that you take the time to help out us noobs.

Regards
Brian

On Monday, 10 August 2015 20:00:41 UTC+12, Steve Piercy wrote: