Forum: Mongrel ERROR: Failed to build gem native extension.

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.

On Thu, Dec 2, 2010 at 9:48 PM, Luis Flores
<luis.fernando.flores.oviedo@gmail.com> 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 Lavena
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

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

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