# Problem installing buildr with rubygem on Windows XP

**URL:** <https://www.ruby-forum.com/t/problem-installing-buildr-with-rubygem-on-windows-xp/137577>\
**Category:** Ruby\
**Created:** [May 14, 2008, 10:48am UTC](https://www.ruby-forum.com/t/problem-installing-buildr-with-rubygem-on-windows-xp/137577 "2008-05-14T10:48:03Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![maxxo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@maxxo](https://www.ruby-forum.com/u/maxxo)\
**Post date:** [May 14, 2008, 10:48am UTC](https://www.ruby-forum.com/t/problem-installing-buildr-with-rubygem-on-windows-xp/137577/1 "2008-05-14T10:48:03Z")

</div>

Hallo,

I try to install the ruby building tool buildr with rubygems on Windows  
XP.  
When I type “gem install buildr” within the console I get following  
error message:

* * *

Building native extensions. This could take a while…  
ERROR: Error installing rjb:  
ERROR: Failed to build gem native extension.

C:/Programme/ruby/bin/ruby.exe extconf.rb install rjb  
checking for jni.h… no  
\*\*\* extconf.rb failed \*\*\*  
Could not create Makefile due to some reason, probably lack of  
necessary libraries and/or headers. Check the mkmf.log file for more  
details. You may need configuration options.

Provided configuration options:  
–with-opt-dir  
–without-opt-dir  
–with-opt-include  
–without-opt-include=${opt-dir}/include  
–with-opt-lib  
–without-opt-lib=${opt-dir}/lib  
–with-make-prog  
–srcdir=.  
–curdir  
–ruby=C:/Programme/ruby/bin/ruby

## Gem files will remain installed in C:/Programme/ruby/lib/ruby/gems/1.8/gems/rjb- 1.1.3 for inspection. Results logged to C:/Programme/ruby/lib/ruby/gems/1.8/gems/rjb-1.1.3/ext/gem\_mak e.out

I know that buildr needs native C extensions, but according to the  
official buildr homepage  
“[http://incubator.apache.org/buildr/getting\_started.html#windows](http://incubator.apache.org/buildr/getting_started.html#windows)” you  
should be asked on which platform buildr should be installed and on  
mswin32 buildr should come with precompiled dlls. But I wasn’t asked!  
Even when I type “gem install buildr --platform mswin32” the same error  
occures.

Is there anybody with experience in installing buildr on Windows?

Thank you for your help.  
maxxo

---

<div class="post-metadata">

**Author:** ![maxxo](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/c89c15/32.png) [@maxxo](https://www.ruby-forum.com/u/maxxo)\
**Post date:** [May 14, 2008, 12:25pm UTC](https://www.ruby-forum.com/t/problem-installing-buildr-with-rubygem-on-windows-xp/137577/2 "2008-05-14T12:25:08Z")

</div>

-----BEGIN PGP SIGNED MESSAGE-----  
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King Dan wrote:  
| Hallo,  
|  
| I know that buildr needs native C extensions, but according to the  
| official buildr homepage  
| “[http://incubator.apache.org/buildr/getting\_started.html#windows](http://incubator.apache.org/buildr/getting_started.html#windows)” you  
| should be asked on which platform buildr should be installed and on  
| mswin32 buildr should come with precompiled dlls. But I wasn’t asked!

Newer RubyGems versions don’t ask for the platform.

See here for possible workarounds:  
[http://groups.google.com/group/ruby-talk-google/browse\_thread/thread/bfdf1fd27fc678a0/47defb992f6f04e2](http://groups.google.com/group/ruby-talk-google/browse_thread/thread/bfdf1fd27fc678a0/47defb992f6f04e2)

* * *

Phillip G.  
Twitter: [twitter.com/cynicalryan](http://twitter.com/cynicalryan)  
Blog: [http://justarubyist.blogspot.com](http://justarubyist.blogspot.com)

~ - You know you’ve been hacking too long when…  
…you send your SO notes like: while !(together(you,me)) miss(you);  
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