# ERROR: Failed to build gem native extension

**URL:** <https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/140561>\
**Category:** Rails\
**Created:** [June 16, 2008, 9:38am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/140561 "2008-06-16T09:38:15Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ramesh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@ramesh](https://www.ruby-forum.com/u/ramesh)\
**Post date:** [June 16, 2008, 9:38am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/140561/1 "2008-06-16T09:38:15Z")

</div>

Hi,  
I’m trtying to install postgress v0.7.9.2008.01.28 gems:

C:\>gem install -v=0.7.9.2008.01.28 postgres  
Building native extensions. This could take a while…  
ERROR: While executing gem … (Gem::Installer::ExtensionBuildError)  
ERROR: Failed to build gem native extension.

ruby extconf.rb install -v=0.7.9.2008.01.28 postgres  
checking for main() in /ms/libpq.lib… no  
Could not find PostgreSQL build environment (libraries & headers):  
Makefile  
not  
created  
\*\*\* 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:/ruby/bin/ruby  
–with-pgsql-dir  
–without-pgsql-dir  
–with-pgsql-include  
–without-pgsql-include=${pgsql-dir}/include  
–with-pgsql-lib  
–without-pgsql-lib=${pgsql-dir}/lib  
–with-/ms/libpqlib  
–without-/ms/libpqlib

Gem files will remain installed in  
c:/ruby/lib/ruby/gems/1.8/gems/postgres-0.7.9  
.2008.01.28 for inspection.  
Results logged to  
c:/ruby/lib/ruby/gems/1.8/gems/postgres-0.7.9.2008.01.28/ext/g  
em\_make.out

The mkmf.log file has following info:

## have\_library: checking for main() in /ms/libpq.lib…

no

“cl -nologo -Feconftest -I. -Ic:/ruby/lib/ruby/1.8/i386-mswin32 -I.  
-Ic:/ruby/lib/ruby/1.8/i386-mswin32 -MD -Zi -O2b2xg- -G6 conftest.c  
msvcrt-ruby18-static.lib /ms/libpq.lib oldnames.lib user32.lib  
advapi32.lib  
ws2\_32.lib -link -libpath:“C:/PROGRA~1/POSTGR~1/8.1/lib”  
-libpath:“c:/ruby/lib” -stack:0x2000000”  
checked program was:  
/\* begin _/  
1: /top/  
2: int main() { return 0; }  
3: int t() { main(); return 0; }  
/_ end \*/

“cl -nologo -Feconftest -I. -Ic:/ruby/lib/ruby/1.8/i386-mswin32 -I.  
-Ic:/ruby/lib/ruby/1.8/i386-mswin32 -MD -Zi -O2b2xg- -G6 conftest.c  
msvcrt-ruby18-static.lib /ms/libpq.lib oldnames.lib user32.lib  
advapi32.lib  
ws2\_32.lib -link -libpath:“C:/PROGRA~1/POSTGR~1/8.1/lib”  
-libpath:“c:/ruby/lib” -stack:0x2000000”  
checked program was:  
/\* begin _/  
1: #include \<winsock2.h\>  
2: #include \<windows.h\>  
3:  
4: /top/  
5: int main() { return 0; }  
6: int t() { void ((volatile p)()); p = (void (()()))main; return 0;  
}  
/_ end \*/

* * *

Can anyone help me??? I’m really strugling a lot.

Thanks in Advance!!!

---

<div class="post-metadata">

**Author:** ![ramesh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@ramesh](https://www.ruby-forum.com/u/ramesh)\
**Post date:** [June 17, 2008, 9:02am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/140561/2 "2008-06-17T09:02:18Z")

</div>

You need to download windows-compiled gem with sth like ‘mswin32’ in  
the name, becouse you use windows, don’t you?  
Look here:  
[http://wiki.rubyonrails.org/rails/pages/PostgreSQL](http://wiki.rubyonrails.org/rails/pages/PostgreSQL) (scroll down and  
then…)  
[http://glauche.de/2007/12/21/installing-native-postgres-gem-for-ruby/](http://glauche.de/2007/12/21/installing-native-postgres-gem-for-ruby/)