# Cannot launch IRB on Mac OS X Leopard

**URL:** <https://www.ruby-forum.com/t/cannot-launch-irb-on-mac-os-x-leopard/138811>\
**Category:** Rails\
**Created:** [May 28, 2008, 12:17am UTC](https://www.ruby-forum.com/t/cannot-launch-irb-on-mac-os-x-leopard/138811 "2008-05-28T00:17:14Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![crucoba](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e8c25b/32.png) [@crucoba](https://www.ruby-forum.com/u/crucoba)\
**Post date:** [May 28, 2008, 12:17am UTC](https://www.ruby-forum.com/t/cannot-launch-irb-on-mac-os-x-leopard/138811/1 "2008-05-28T00:17:14Z")

</div>

I successfully installed Ruby 1.8.6 and Rails 2.0.2 and RubyGems 1.0.1.  
Launched ruby script/server. Got successful Welcome Aboard ROR page in  
browser. Opened second Terminal window and tried to launch irb. Got  
this failure message:

```
$ irb
dyld: NSLinkModule() error
dyld: Symbol not found: _rl_filename_completion_function
  Referenced from:

```

/usr/local/lib/ruby/1.8/i686-darwin9.2.2/readline.bundle  
Expected in: flat namespace

```
Trace/BPT trap

```

I tried this in all directories from the app directory on up. Even  
tried with sudo

Any ideas?

---

<div class="post-metadata">

**Author:** ![crucoba](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e8c25b/32.png) [@crucoba](https://www.ruby-forum.com/u/crucoba)\
**Post date:** [May 28, 2008, 12:21am UTC](https://www.ruby-forum.com/t/cannot-launch-irb-on-mac-os-x-leopard/138811/2 "2008-05-28T00:21:54Z")

</div>

Ruby comes with Leopard, you shouldn’t of needed to install anything.  
When you say you installed it yourself what did you do exactly to  
accomplish this?

What happens when you type:

ruby --version

You should see this:  
ruby 1.8.6 (2007-09-24 patchlevel 111) [universal-darwin9.0]

If not you didn’t install it correctly. Let me know if you get that  
far and I’ll see what else I can think of.

Nicholas

On May 27, 5:17 pm, David C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

---

<div class="post-metadata">

**Author:** ![crucoba](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/e8c25b/32.png) [@crucoba](https://www.ruby-forum.com/u/crucoba)\
**Post date:** [May 28, 2008, 12:40am UTC](https://www.ruby-forum.com/t/cannot-launch-irb-on-mac-os-x-leopard/138811/3 "2008-05-28T00:40:29Z")

</div>

ncancelliere wrote:

> Ruby comes with Leopard, you shouldn’t of needed to install anything.  
> When you say you installed it yourself what did you do exactly to  
> accomplish this?
> 
> What happens when you type:
> 
> ruby --version
> 
> You should see this:  
> ruby 1.8.6 (2007-09-24 patchlevel 111) [universal-darwin9.0]
> 
> If not you didn’t install it correctly. Let me know if you get that  
> far and I’ll see what else I can think of.
> 
> Nicholas
> 
> On May 27, 5:17�pm, David C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

My version is: ruby 1.8.6 (2008-03-03 patchlevel 114)  
[i686-darwin9.2.2]. It is newer than from Leopard and I followed  
precisely the instructions in Patrick Lenz book “Simply Rails 2”. I do,  
indeed get the opening splash in the browser ([http://localhost:3000](http://localhost:3000))  
and "About your application’s environment reports this:  
Ruby version 1.8.6 (i686-darwin9.2.2)  
RubyGems version 1.0.1  
Rails version 2.0.2  
Active Record version 2.0.2  
Action Pack version 2.0.2  
Active Resource version 2.0.2  
Action Mailer version 2.0.2  
Active Support version 2.0.2  
Application root /Users/david/shovell  
Environment development  
Database adapter sqlite3

But I cannot get past this point.