Comment 3 for bug 1786224

So, I've made my upgrade from 16.04 to 18.04 and I can reproduce the issue.

This is because during the upgrade the extras ppa (un-officials) are deactivated and the packages installed from these ppa are removed.

Except liboqapy-iproc0. I don't know why.

And, when you reinstall oqapy, apt don't reinstall this lib.

sudo apt-get install liboqapy-iproc0 solve the issue.