Downgrade to a specific date

[paxmark1]

So, you are in rolling and some sneaky bug got past Sid and KABLOOM, you have problems.  This might help you
Via Planet Debian   Original post is probably in French, so that is an option  He is an active Debian Dev. 
https://vincent.bernat.ch/en/blog/2020-downgrade-debian

Let's suppose we want to go back to January, 20th 2020. In /etc/apt/sources.list.d/snapshot.list, we add a date-specific snapshot as a source:

Code Select Expand

deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20200120T111800Z/ unstable main contrib non-free

Note: the forum mangles urls at times   - the "unstable main contrib non-free" belongs in the URL of the  deb line

No I have not done it yet.  So if it does not work, don't blame me, but I will probably try it in Sid sometime.  Merde, I worked over 80 hours last week.     
peace out