May have created a hybrid system state


I added debian sid repos to my sources.list to get the latest version of firefox. I thought I did the proper thing to just install firefox by using:
apt install -t sid firefox
But after a recent upgrade I think I may have created a hybrid sid/stretch system. Apt is constantly complaining about holding broken packages, and it seems like I have updated versions of things like python3 that are preventing package installation.
apt update && apt full-upgrade doesn’t help, nor does apt-get -f install
Is there any hope of restoring a consistent debian 9 based system?

Learning debian the hard way…



Reinstalled pureOS; I’ll just be conservative and stick with stretch repos.


Yes, mixing repos is a bad idea. Re-installation can help.