From: Brian Mitchell <binary42@...>
Date: 2006-04-09T22:28:39+09:00
Subject: Re: [ruby 1.8.4] bug: power! does not work then works in irb

Hi,

You probably saw my reply on IRC but for others...

2006/4/9, solsTiCe d'Hiver <solstice.dhiver@laposte.net>:
> hi.
>
> here is a session in irb:
> irb(main):001:0> 10.power!(200)
> NoMethodError: undefined method `power!' for 10:Fixnum
>         from (irb):1
> irb(main):002:0> help Fixnum
> => nil

This is actually a valid call. To see what help is from try:

method :help

You might get something like:

#<Method: Object(IRB::ExtendCommandBundle)#help>

The part in () tells us that it is from IRB... a quick check shows
that a trail is started
that eventually leads to:

require 'mathn'

That file in turn, does something like:

alias power! **

The reason not all people got the error is because some were probably
loading other code at startup or before testing. Rubygems is an
example of this.

Moral of the story is to be away of what your ruby environment
automatically brings in.

Brian.