# Undefined symbol: rb\_str\_set\_len

**URL:** <https://www.ruby-forum.com/t/undefined-symbol-rb-str-set-len/154042>\
**Category:** Rails\
**Created:** [November 24, 2008, 8:18pm UTC](https://www.ruby-forum.com/t/undefined-symbol-rb-str-set-len/154042 "2008-11-24T20:18:25Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![renec](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8baadc/32.png) [@renec](https://www.ruby-forum.com/u/renec)\
**Post date:** [November 24, 2008, 8:18pm UTC](https://www.ruby-forum.com/t/undefined-symbol-rb-str-set-len/154042/1 "2008-11-24T20:18:25Z")

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I recently downgraded from ruby 1.8.7-p72 to 1.8.6-p287 and now whenever  
i try to access the mysqldatabase my rails server (WEBrick) crashes with  
the following error:

ruby: symbol lookup error:  
/usr/lib/ruby/site\_ruby/1.8/i686-linux/mysql.so: undefined symbol:  
rb\_str\_set\_len

i first thought it was some sort of linking error or something due to  
the downgrade, but i just made another DB from scratch and keep getting  
the same result.

Does anyone have an idea of what could be the problem or how to fix it?

-R

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<div class="post-metadata">

**Author:** ![renec](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8baadc/32.png) [@renec](https://www.ruby-forum.com/u/renec)\
**Post date:** [November 24, 2008, 8:33pm UTC](https://www.ruby-forum.com/t/undefined-symbol-rb-str-set-len/154042/2 "2008-11-24T20:33:59Z")

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Probably because your mysql gem has been built against 1.8.6. I’d try  
reinstalling the mysql gem.

Fred

Sent from my iPhone

On 24 Nov 2008, at 19:18, Rene Cienfuegos  
\<removed\_email\_address@domain.invalid

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<div class="post-metadata">

**Author:** ![renec](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8baadc/32.png) [@renec](https://www.ruby-forum.com/u/renec)\
**Post date:** [November 24, 2008, 10:31pm UTC](https://www.ruby-forum.com/t/undefined-symbol-rb-str-set-len/154042/3 "2008-11-24T22:31:08Z")

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I tried that too, but didn’t work.

The thing that i did right after i posted the message was to remove the  
mysql.so in /usr/lib/ruby/site\_ruby/1.8/i686-linux/ probably not the  
best solution, but it worked.

thanks for the answer

-R