Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

Linking Tobii eyetracker to OpenSesame on Mac OS

edited December 2019 in OpenSesame

Hi OpenSesame team!

We're currently setting up some OpenSesame experiments using a Tobii eyetracker, to test how babies make predictions and respond to rewarding stimuli. We are having issues with setting up the tobii-research python package in OpenSesame. The research computer is a new Mac OS Catalina version 10.15, with the latest Opensesame version 3.2. 

We first tried to use the Python package manager, but immediately got a box pop-up with the error below:

Extension error
exception type: URLError
exception message: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED]
certificate verify failed (_ssl.c:726)>
time: Mon Dec 2 16:19:45 2019
 File "/Applications/", line 322, in
 File "/Applications/
opensesame_extensions/package_manager/", line 39, in
 File "/Applications/
opensesame_extensions/package_manager/", line 18, in init
 self._qpipwidget = QPipWidget()
 File "/Applications/", line 35, in __init__ = PackageManager()
 File "/Applications/", line 30, in __init__
 self._cheeseshop = pypi.CheeseShop()
 File "/Applications/", line 105, in __init__
 File "/Applications/", line 120, in get_cache
 File "/Applications/", line 159, in fetch_pkg_list
 package_list = self.list_packages()
 File "/Applications/", line 179, in list_packages
 return self.xmlrpc.list_packages()
 File "/Applications/", line 1243, in __call__
 return self.__send(self.__name, args)
 File "/Applications/", line 1602, in __request
 File "/Applications/", line 66, in request
 fhandle =
 File "/Applications/", line 429, in open
 response = self._open(req, data)
 File "/Applications/", line 447, in _open
 '_open', req)
 File "/Applications/", line 407, in _call_chain
 result = func(*args)
 File "/Applications/", line 1241, in https_open
 File "/Applications/", line 1198, in do_open
 raise URLError(err)
URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify
failed (_ssl.c:726)>


  • edited December 2019

    We then tried to install tobii-research directly from in the OpenSesame debug window, using internal pip commands described here: We got the following Environment error:

    >>import pip
    >>pip._internal.main(['install', 'tobii-research'])
    Collecting tobii-research
    tobii_research-1.7.0-cp27-cp27m-macosx_10_13_intel.whl (1.2MB)
    Could not install packages due to an EnvironmentError: [Errno 2] No such file or
    directory: '/private/var/folders/jz/khj5prc531n1vv9661s91tgh7y_24p/T/pip-reqtracker-dXcyuR/

    Have you happened to come across this error before? We checked and there is indeed no folder 'pip-reqtracker-dXcyuR' in this path. 

    We would be very grateful for some help on either of these issues, whatever is easiest to get Tobii linked up!

    Best wishes,


    P.S We will also be including fNIRS data collection along with this, so might come back to discuss that at some point, but think we will just start that piloting with the old "pushing the buttons at the same time" technique :)

  • UPDATE: As a workaround, I got the internal pip function working on a different Mac (Mac Pro 10.13.6 High Sierra) and also with the previous OpenSesame release (3.2.7). From that it seems that the only place the tobii files reside is in: /Applications/ (as expected for a python package...), but perhaps you could confirm at some stage if you know whether there are any dependencies in other folders that I might not be aware of. 



  • Hi Bronagh,

    The Python package manager is not very reliable, so let's forget about the first error for now. In any case, this is unrelated to the second error. Here, I suspect that the problem is a Mac OS-specific issue with the tobii_research package itself. But since I don't have a Mac, it's difficult to say more about it. @Daniel Does this error look familiar to you?

    As an ugly workaround (but I guess you did that already?) copying the tobii_research folder from the site-packages of one OpenSesame installation to another should probably work.



    PS. Welcome to the forum!

  • Thanks Sebastiaan! I missed that I would not get a notification on a response to this post :) I went ahead and copied the folder for now. I get the feeling I'll be in touch more in the coming couple of months, although the issues will likely be related to MacOs and the media player, so will probably be directed towards Daniel...

    Have fun at NVP if you're going this year!


  • Have fun at NVP if you're going this year!

    I am! You?

  • Not this time unfortunately :( I'm caught up with a few too many things to do before the year is out. It's my first time not going since 2013, I'll miss it!

    Enjoy the disco-bowling and the catch-ups :)

Sign In or Register to comment.