On May 22, 11:59  쮮
> I use a fresh installation of ruby 1.9.2p180 to make some tests with
> web-frameworks on a windows machine.
>

Please: stop adding "BARRIER" to your posts, it is clear you're having
problems and there is no need to overstate them.

> Most installation of libraries went through without problems.
>
> Except: json and thin (the eventmachine part)
>

The binaries for JSON ddin't work across versions of Ruby (1.8.x and
1.9.x) and that is the reason these binaries were requested to be
removed:

http://help.rubygems.org/discussions/problems/541-the-case-about-yanking-json-windows-binaries

In the current version of EventMachine there is no binaries, but pre-
release version (1.0.x) does provides binaries, so does Thin:

https://rubygems.org/gems/thin/versions/1.2.11-x86-mingw32
https://rubygems.org/gems/eventmachine/versions/1.0.0.beta.3-x86-mingw32

> "
> Fetching: eventmachine-0.12.10.gem (100%)
> ERROR:    > The 'eventmachine' native gem requires installed build tools.
> "
>

You're removing the part that state how to install development tools
to be able to successfully compile it.

It was intentional?

If you're working on other platform than Windows, it will be required
for you to have development tools to compile these gems. In this case,
and by current releases, it is required, but newer releases might not
require them.

--
Luis Lavena