pg_upgrade across more than two neighboring major releases

Hello all,

don't know much about pg_upgrade implementation so I rather asking here before
I start trying the process once again with debugging and observing deeply
the code.

I tried to setup our postgresql RPM to package pg_upgrade in version
8.4.13 to automatize post-rpm-upgrade update of postgresql's data to
9.2.4.  I was unable to reach successful result (getting weird errors).

Is pg_upgrade supposed to work even across multiple major releases?  (I know
that the README.rpm-dist is mentioning just one major release step, but it
could be bound just to actual pg_upgrade which is packaged..)

I can imagine that it may be difficult to handle everything even between two
following major releases - thus if it was possible, I would consider it as
heartwarming :).

Thanks for your answer,
Pavel