# Irb crash

**URL:** <https://www.ruby-forum.com/t/irb-crash/94622>\
**Category:** Ruby\
**Created:** [May 9, 2006, 7:39am UTC](https://www.ruby-forum.com/t/irb-crash/94622 "2006-05-09T07:39:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![curi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e68b1a/32.png) [@curi](https://www.ruby-forum.com/u/curi)\
**Post date:** [May 9, 2006, 7:39am UTC](https://www.ruby-forum.com/t/irb-crash/94622/1 "2006-05-09T07:39:31Z")

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I’m new so I don’t know if/where I should report this…

if I type:

String = Hash

in irb twice it crashes. it crashed with other stuff besides Hash,  
too. just doing it twice at once with a semicolon doesn’t crash  
immediately.

OS X 10.4.6  
ruby 1.8.4 (2005-12-24) [powerpc-darwin8.5.0]  
irb 0.9.5(05/04/13)

curi-g5:~ curi$ irb  
irb(main):001:0\> String = Hash  
(irb):1: warning: already initialized constant String  
=\> Hash  
irb(main):002:0\> String = Hash  
/usr/local/lib/ruby/1.8/irb/ruby-token.rb:101:in `Token': undefined method `ancestors’ for “=”:String (NoMethodError)  
from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:400:in `lex_init' from /usr/local/lib/ruby/1.8/irb/slex.rb:237:in `match\_io’  
from /usr/local/lib/ruby/1.8/irb/slex.rb:222:in `match_io' from /usr/local/lib/ruby/1.8/irb/slex.rb:76:in `match’  
from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:287:in `token' from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:263:in `lex’  
from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:234:in  
`each_top_level_statement' from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:230:in `each\_top\_level\_statement’  
from /usr/local/lib/ruby/1.8/irb/ruby-lex.rb:229:in  
`each_top_level_statement' from /usr/local/lib/ruby/1.8/irb.rb:146:in `eval\_input’  
from /usr/local/lib/ruby/1.8/irb.rb:70:in `start' from /usr/local/lib/ruby/1.8/irb.rb:69:in `start’  
from /usr/local/bin/irb:13  
curi-g5:~ curi$

– Elliot T.

> **[Curiosity Blog – Elliot Temple](https://www.curi.us/blog/)**
>
> A philosophy blog

---

<div class="post-metadata">

**Author:** ![curi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e68b1a/32.png) [@curi](https://www.ruby-forum.com/u/curi)\
**Post date:** [May 9, 2006, 7:58am UTC](https://www.ruby-forum.com/t/irb-crash/94622/2 "2006-05-09T07:58:04Z")

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Hi,

In message “Re: irb crash”  
on Tue, 9 May 2006 14:36:33 +0900, Elliot T. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|I’m new so I don’t know if/where I should report this…  
|  
|if I type:  
|  
|String = Hash  
|  
|in irb twice it crashes. it crashed with other stuff besides Hash,  
|too. just doing it twice at once with a semicolon doesn’t crash  
|immediately.

Re-assigning predefined class like String should cause serious  
problems such as you’ve seen. Ruby allows you to shoot your foot.

```
						matz.

```