I am really disappointed that rails 3.0 have a problem, big issue
with mysql2.
I googled and surprised that none of the ruby core developers
mentioning this problem
at least telling to people about this issue and solution to this

Is there anybody who can tell what is going on?

I solved the problem - libmysqlclient-dev package should be installed.
After that run the command:

rvm 1.9.2-head gem install mysql2

forgot to say im quoting javix he had your problem and solve it

I agree with you. I lost almost an hour looking for how to resolve
this problem. Just here I`ve found the solution.

at least its solved right?

radhames brito wrote:

at least its solved right?

you are talking about window or linux ?