# ERROR: Failed to build gem native extension **URL:** \ **Category:** Mongrel\ **Created:** [December 3, 2010, 2:07am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/200022 "2010-12-03T02:07:38Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Dobai-Pataky\_BSSSSl](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/77aa72/32.png) [@Dobai-Pataky\_BSSSSl](https://www.ruby-forum.com/u/Dobai-Pataky_BSSSSl)\ **Post date:** [December 3, 2010, 2:07am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/200022/1 "2010-12-03T02:07:38Z")
Hello, I am currently not able to instal mongrel, I run a Linux Ubuntu 10.04 system with Gems 1.3.7 when I do a “sudo gem install mongrel” I get this sequence of messages: $ sudo gem install mongrel Building native extensions. This could take a while… ERROR: Error installing mongrel: ERROR: Failed to build gem native extension. /usr/local/bin/ruby extconf.rb checking for main() in -lc… yes creating Makefile make gcc -I. -I/usr/local/include/ruby-1.9.1/i686-linux -I/usr/local/include/ruby-1.9.1/ruby/backward -I/usr/local/include/ruby-1.9.1 -I. -D\_FILE\_OFFSET\_BITS=64 -fPIC -O3 -ggdb -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -o http11.o -c http11.c http11.c: In function http\_field: http11.c:70: warning: format not a string literal and no format arguments http11.c:71: warning: format not a string literal and no format arguments http11.c:77: error: struct RString has no member named ptr http11.c:77: error: struct RString has no member named len http11.c: In function request\_uri: http11.c:102: warning: format not a string literal and no format arguments http11.c: In function fragment: http11.c:113: warning: format not a string literal and no format arguments http11.c: In function request\_path: http11.c:124: warning: format not a string literal and no format arguments http11.c: In function query\_string: http11.c:135: warning: format not a string literal and no format arguments http11.c: In function header\_done: http11.c:172: error: struct RString has no member named ptr http11.c:172: error: struct RString has no member named ptr http11.c:172: error: struct RString has no member named ptr http11.c:174: error: struct RString has no member named ptr http11.c:176: error: struct RString has no member named ptr http11.c:177: error: struct RString has no member named len http11.c: In function HttpParser\_execute: http11.c:298: error: struct RString has no member named ptr http11.c:299: error: struct RString has no member named len http11.c:307: warning: format not a string literal and no format arguments make: \*\*\* [http11.o] Error 1 Gem files will remain installed in /usr/local/lib/ruby/gems/1.9.1/gems/mongrel-1.1.5 for inspection. Results logged to /usr/local/lib/ruby/gems/1.9.1/gems/mongrel-1.1.5/ext/http11/gem\_make.out Would you please help me? Thank you in advance for your valuable time. ---
**Author:** ![Luis\_Flores](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c37758/32.png) [@Luis\_Flores](https://www.ruby-forum.com/u/Luis_Flores)\ **Post date:** [December 3, 2010, 2:40am UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/200022/2 "2010-12-03T02:40:45Z")
On Thu, Dec 2, 2010 at 9:48 PM, Luis Flores [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hello, I am currently not able to instal mongrel, I run a Linux Ubuntu 10.04 > system with Gems 1.3.7 when I do a “sudo gem install mongrel” I get this > sequence of messages: [SNIP] > $ sudo gem install mongrel > gcc -I. -I/usr/local/include/ruby-1.9.1/i686-linux > -I/usr/local/include/ruby-1.9.1/ruby/backward > -I/usr/local/include/ruby-1.9.1 -I. -D\_FILE\_OFFSET\_BITS=64 -fPIC -O3 -ggdb > -Wextra -Wno-unused-parameter -Wno-parentheses -Wpointer-arith > -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -o http11.o > -c http11.c > /usr/local/lib/ruby/gems/1.9.1/gems/mongrel-1.1.5/ext/http11/gem\_make.out > > Would you please help me? Mongrel 1.1.5 is not compatible with Ruby 1.9.x You need to install the pre-release version: ## gem install mongrel --pre ## Luis L. AREA 17 Perfection in design is achieved not when there is nothing more to add, but rather when there is nothing more to take away. Antoine de Saint-Exupry ---
**Author:** ![Luis\_Flores](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c37758/32.png) [@Luis\_Flores](https://www.ruby-forum.com/u/Luis_Flores)\ **Post date:** [February 24, 2011, 12:43pm UTC](https://www.ruby-forum.com/t/error-failed-to-build-gem-native-extension/200022/3 "2011-02-24T12:43:06Z")
I was racking my brain around with this one for a while and finally got it working on Ubuntu 10.10… $ cd /var/lib/gems/1.9.1/cache #it could be 1.9.1 or another directory #depending on how you intalled ruby $ pwd #make damn sure you are in the right one 😉 /var/lib/gems/1.9.1/cache/ $ sudo rm \* $ gem install mongrel -v 1.2.0.pre2 --pre --source [http://rubygems.org](http://rubygems.org) I am pretty sure the post above will work too i.e $ gem install mongrel --pre I didn’t get a chance to try it but the key is if your having problems even with the --pre its because gems is looking in its cache files to save you time and thus --pre doesn’t help