Unable to downgrade firefox version using apt-get in Ubuntu

Note: This is not duplicate of How do I downgrade Firefox v. 57 to v. 56?.

I have installed firefox using sudo apt-get install firefox Right now it is installing version 63.0 which has some issue with selenium webDriver.

So I want to downgrade because this selenium webDriver is working fine with version 57.0.4.

I tried sudo apt-get install firefox=57.0.4+build1-0ubuntu0.16.04.1 which is not working and saying that:

E: Version '57.0.4+build1-0ubuntu0.16.04.1' for 'firefox' was not found

The strange thing is that I am able to install version 45 using sudo apt install firefox=45.0.2+build1-0ubuntu1

I have taken the syntax from Here.

Any help will be highly appreciated!

2 Answers

You could just remove your current firefox's version and install deb package: sudo apt remove firefox && wget && sudo dpkg -i firefox_57.0.4+build1-0ubuntu0.16.04.1_amd64.deb

You should read Debian Wiki. The Key for future similar to gentoo is the file  /etc/apt/preferences (similar to mask)