How do you downgrade rubygems?

Question

I have rubygems 1.3.1 installed but I want to go back to 1.2.0. What's the command to downgrade rubygems?

Wonderment

Is there any particular reason why you need to downgrade (maybe because of the behavior of putting gems in ~/.gems when you forget sudo)? – Windowlight

This would be a reason why: #4860100 – Utu

Answer 1

Updated November 2011: Now that RVM's out, try running rvm install rubygems <version>.

Tamekia

Eh, much better to sudo gem update --system 1.4.2 or rvm install rubygems 1.4.2 – Longitude

Answer 2

This worked for me when downgrading from 1.5.2 to 1.4.2 because of old rails version:

sudo gem update --system 1.4.2

More information about downgrading/upgrading rubygems: https://github.com/rubygems/rubygems/blob/master/UPGRADING.md

Borodino

Thanks! This worked for me. Have an old Rails 2.2.2 project that complained without this. I still don't know why actually (if anyone has details on that I'd be curious) but at least it works now. – Downcome

@BrianArmstrong There is also a bug in 2.3.x which is already fixed in the rails 2-3-stable branch (see link). Perhaps this fix will be available in the next release of 2.2.x. – Borodino

This seems like the most reliable way. – Pre

does this do it just for a particular gemset though? or would i need to go back and forth between rubygems if I want to switch between rails 2 and rails 3 development? – Inoperative

@DJTripleThreat see https://mcmap.net/q/212312/-use-multiple-versions-of-rubygems-with-rvm for rvm. when you use rbenv it should be enough to copy the ruby installation. when you don't use rbenv nor rvm than I would suggest you to use rbenv because otherwise you need to go back and forth with the system ruby – Borodino

getting segment fault :( – Sanctum

Answer 3

If you're using RVM, then you can do this to remove current ruby gems, then upgrade/downgrade rubygems:

rvm install rubygems 1.4.2

Lancaster

just googled this to try and get rid of a ton of deprecation warnings caused by recent rubygems updates, saved me a lot of hassle, thanks :) – Scirrhus

Answer 4

This just worked for me on OSX to get from 1.5.0 back to 1.4.2

sudo gem uninstall -v '1.5.0' rubygems-update
sudo gem update --system --local

Herbartian

Answer 5

I had a similar problem in an old Rails 3 stack. When these type of issues occur, my recommendation is to go onto the production server that the application is currently running in and check out which rubygems version it is using:

gem -v

For me, it was using 1.8.24. So all I needed to do is downgrade my current rubygems which was generated from "rvm install 1.9.3", when I installed the old ruby for this app. I ran the following command:

 $ rvm install rubygems 1.8.24 --force

And it worked. Note I am running Ubuntu 14.04 and the server I am using is also Ubuntu.

Death

Had to add --force if I wanted to downgrade otherwise rvm wouldn't proceed with the install – Aniakudo

Answer 6

I used this command to go back to the gem version that my ruby version needed:

rvm rubygems current

If it gives checksum errors try

rvm rubygems current --verify-downloads 1

That did the trick for me.

Oto