How to update gem to a version that's not the latest ?

[Gaudi Mi]

I posted an earlier question but am amending it with this question
instead which hopefully gets to the heart of the matter:

I'm trying to get from rubygems version 0.9.5 to version 1.2.0 because I
believe that 1.3.0 has a possible bug. However when I install 0.9.5 and
then do a gem update --system it updates to 1.3.0 because that's the
most recent in my remote repository (we use an internal repository,
btw).

The repository does have 1.2.0. How do I get to version 1.2.0 instead
of 1.3.0?

Thanks.

 

[Rados³aw Bu³at]

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ZG9zs2F3IEJ1s2F0CgpodHRwOi8vcmFkYXJlay5qb2dnZXIucGwgLSBt82ogYmxvZwo=

 

[Gaudi Mi]

Thanks for the response, but the question of "how" was really the heart
of my question. I understand that *gems* can be installed locally by
using the -l switch, but when I try

gem update --system -l [some file name]

it does not work and I'm not clear on the difference between

gem install rubygems-update-0.9.5.gem

and

gem update --system

and

update_rubygems.

Am I the only person that finds this confusing?

Thanks.