Py.test fails on Ubuntu 16.04


myHDL 1.0 dev version has no issue on MacOSX with Python 2.7.10
But on Ubuntu 16.04 with default python3.5.2; didn’t figure out how to run py.test of python 3.6.

py.test fails with error message:

myhdl.CosimulationError: Premature simulation end

/home/user/.local/lib/python3.5/site-packages/myhdl/ CosimulationError

--------------------------------------- Captured stderr call ---------------------------------------
Traceback (most recent call last):
File “/home/user/Workspace/myHDL/myhdl/myhdl/test/core/”, line 31, in
from myhdl import Signal
ImportError: No module named myhdl
============================== 9 failed…

Please comment,


Don’t know exact what was the issue, and walk around.
I guess, myhdl core test had issue with 3.5.2, and my myhdl was not installed for python 2.7.12 so I didn’t following to make py.test working:
# I have multiple versions of python in system 2.7.12; 3.5; 3.6
sudo apt-get install python-pip
# assume this installs pip to 2.7.12, which doesn’t have pip
python -m pip install myhdl

When I rerun myhdl/test/core/py.test still see “platform linux – Python 3.5.2, pytest-3.4.0, py-1.5.2, pluggy-0.6.0” but, 308 passed in 13.29 seconds.


That is odd, travis-ci seems to do ok with 3.6

That is an older run, maybe something changed in the latest version.

I run 3.6 and py.test everyday and have not run into an issue.