Issue #8464 has been updated by knu (Akinori MUSHA).

Category set to lib
Status changed from Open to Feedback
Assignee set to knu (Akinori MUSHA)

IPAddr currently does not support scope ID's.

Making IPAddr deal with scope ID's would mean a lot more than just ignoring it (starting with adding #scope_id).
If you are going to request such a feature, you'll have to investigate, for example, in what contexts (libraries/methods/commands) an IPv6 address with a scope ID is valid and accepted, if #to_s should include it or another method should be added for that, how it would affect the backward compatibility, etc. 

On the other hand, you can use str.sub(/%.*/m, '') or str[/[^%]*/m] if you just want to drop the scope ID part.
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Bug #8464: IPAddr cannot parse link-local IPv6 address.
https://bugs.ruby-lang.org/issues/8464#change-40260

Author: aselder (Andrew Selder)
Status: Feedback
Priority: Normal
Assignee: knu (Akinori MUSHA)
Category: lib
Target version: 
ruby -v: ruby 2.0.0p195 (2013-05-14 revision 40734) [x86_64-darwin12.3.0]
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


1.9.3p374 :001 > require 'ipaddr'
 => true
1.9.3p374 :002 > IPAddr.new("0:0:0:0:0:0:0:1%0")
ArgumentError: invalid address
	from /Users/andrew/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/ipaddr.rb:559:in `in6_addr'
	from /Users/andrew/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/ipaddr.rb:496:in `initialize'
	from (irb):2:in `new'
	from (irb):2
	from /Users/andrew/.rvm/rubies/ruby-2.0.0-p195/bin/irb:16:in `<main>'


Same behavior in Ruby 1.9.3 all patch levels


-- 
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