# 1.8/1.9 compiled library binary compatibility

**URL:** <https://www.ruby-forum.com/t/1-8-1-9-compiled-library-binary-compatibility/115575>\
**Category:** Ruby\
**Created:** [September 26, 2007, 2:35pm UTC](https://www.ruby-forum.com/t/1-8-1-9-compiled-library-binary-compatibility/115575 "2007-09-26T14:35:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![absolute-beginner](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/a5b964/32.png) [@absolute-beginner](https://www.ruby-forum.com/u/absolute-beginner)\
**Post date:** [September 26, 2007, 2:35pm UTC](https://www.ruby-forum.com/t/1-8-1-9-compiled-library-binary-compatibility/115575/1 "2007-09-26T14:35:53Z")

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Hi

I’m wondering whether extension libraries compiled against 1.8 will work  
with 1.9, and/or the other way around.

I know the C API is little-changed, but will people offering add-ons  
binaries need to offer two versions?

Also - if it should work, should I be worried about a particular library  
if it’s not currently working - or just be patient and assume it’s down  
to 1.9 being work in progress?

ta  
alex

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**Author:** ![absolute-beginner](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/a5b964/32.png) [@absolute-beginner](https://www.ruby-forum.com/u/absolute-beginner)\
**Post date:** [September 26, 2007, 3:06pm UTC](https://www.ruby-forum.com/t/1-8-1-9-compiled-library-binary-compatibility/115575/2 "2007-09-26T15:06:36Z")

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Alex F. wrote:

> to 1.9 being work in progress?  
> I was wondering the same thing. More specifically, I was wondering if  
> Mongrel was working with YARV yet. That then got me wondering if the IO  
> patterns Zed S. seemed to be frustrated with in MRI had been fixed in  
> YARV, and whether we’d (fingers crossed) see even more of a speed bump  
> to serving HTTP at some point in the future. Just call me foolishly  
> optimistic if you like 🙂

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<div class="post-metadata">

**Author:** ![absolute-beginner](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/a5b964/32.png) [@absolute-beginner](https://www.ruby-forum.com/u/absolute-beginner)\
**Post date:** [September 26, 2007, 6:19pm UTC](https://www.ruby-forum.com/t/1-8-1-9-compiled-library-binary-compatibility/115575/3 "2007-09-26T18:19:04Z")

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Hi,

At Wed, 26 Sep 2007 21:35:03 +0900,  
Alex F. wrote in [ruby-talk:271038]:

> I’m wondering whether extension libraries compiled against 1.8 will work  
> with 1.9, and/or the other way around.

No, impossible in both cases. For instance, object type flags  
were added/changed in 1.9, and also structs.