# Ruby 1.8.6 : 0.5 == 5.0?

**URL:** <https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241>\
**Category:** Ruby\
**Created:** [September 1, 2010, 2:45pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241 "2010-09-01T14:45:13Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![tcsnide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/eb8c5e/32.png) [@tcsnide](https://www.ruby-forum.com/u/tcsnide)\
**Post date:** [September 1, 2010, 2:45pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241/1 "2010-09-01T14:45:13Z")

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Hello,

I have a strange problem on one of my servers.  
I just installed ruby 1.8.6 from source :

/tmp/ruby-1.8.6-p383$uname -a  
Linux prod2-ctxctrl 2.6.32-24-generic-pae #39-Ubuntu SMP Wed Jul 28  
07:39:26 UTC 2010 i686 GNU/Linux

/tmp/ruby-1.8.6-p383$ruby --version  
ruby 1.8.6 (2009-08-04 patchlevel 383) [i686-linux]

Something is broken with floats, here are a few tests :

/tmp/ruby-1.8.6-p383$ruby -e “puts 0.5”  
5.0  
/tmp/ruby-1.8.6-p383$ruby -e “puts 0.05”  
5.0  
/tmp/ruby-1.8.6-p383$ruby -e “puts 0.5 == 5.0”  
true  
/tmp/ruby-1.8.6-p383$ruby -e “puts 1.0 / 2”  
0.5

Do you have any idea of what is going on?

Thanks  
Thomas

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**Author:** ![tcsnide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/eb8c5e/32.png) [@tcsnide](https://www.ruby-forum.com/u/tcsnide)\
**Post date:** [September 1, 2010, 3:22pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241/2 "2010-09-01T15:22:42Z")

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This seems to work for me for my version and os etc.

ruby 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin10.0.0]  
$ ruby -e “puts 0.5 == 5.0”  
false  
$

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**Author:** ![tcsnide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/eb8c5e/32.png) [@tcsnide](https://www.ruby-forum.com/u/tcsnide)\
**Post date:** [September 1, 2010, 3:30pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241/3 "2010-09-01T15:30:54Z")

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Hi,

2010/9/1 Thomas S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> ruby 1.8.6 (2009-08-04 patchlevel 383) [i686-linux]  
> 0.5
> 
> Do you have any idea of what is going on?

This is a gcc version issue with gcc 4.4.1.

Refer to [Something broke ruby floats - Ruby - Ruby-Forum](http://www.ruby-forum.com/topic/199860)

Regards,  
Park H.

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**Author:** ![tcsnide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/eb8c5e/32.png) [@tcsnide](https://www.ruby-forum.com/u/tcsnide)\
**Post date:** [September 1, 2010, 3:52pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241/4 "2010-09-01T15:52:34Z")

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Le 1 sept. 10 à 15:27, Heesob P. a écrit :

> > 07:39:26  
> > 5.0
> 
> Regards,  
> Park H.

This is it!

Thanks,  
Thomas

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**Author:** ![tcsnide](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/eb8c5e/32.png) [@tcsnide](https://www.ruby-forum.com/u/tcsnide)\
**Post date:** [September 1, 2010, 3:50pm UTC](https://www.ruby-forum.com/t/ruby-1-8-6-0-5-5-0/194241/5 "2010-09-01T15:50:49Z")

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On Wed, Sep 1, 2010 at 6:44 AM, Thomas S.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ruby 1.8.6 (2009-08-04 patchlevel 383) [i686-linux]  
> 0.5
> 
> Do you have any idea of what is going on?

GCC. The version of GCC that you built with does fun and entertaining  
things with floating point numbers in the p383 (and many other patch  
levels of 1.8.6 and 1.8.7) source. Try pulling from SVN and building  
that one:

svn co [http://svn.ruby-lang.org/repos/ruby/branches/ruby\_1\_8\_6](http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_8_6)

Let me know if you still experience the bizarre floating point behavior.

Kirk H.