Gem installation oddity

Ruby
#1

I have been totally puzzled by what I think is a misconfiguration of my
gem environment. I’ve read and looked and experimented and tried to
solve this. Maybe you can help… Here’s the top level symptom. I install
a gem, and then do a ‘which’ and gem says it can’t find it:

sudo gem install wxruby
Successfully installed wxruby-2.0.0-universal-darwin-9
1 gem installed
Installing ri documentation for wxruby-2.0.0-universal-darwin-9…
Installing RDoc documentation for wxruby-2.0.0-universal-darwin-9…
/opt/local/lib/ruby/gems/1.8$ gem which wxruby
Can’t find ruby library file or shared library wxruby
/opt/local/lib/ruby/gems/1.8$

This is not a peculiarity with this particular gem. There are others in
this odd state too. Here’s some more context:

GEM ENVIRONMENT

/opt/local/lib/ruby/gems/1.8$ gem environment
RubyGems Environment:

  • RUBYGEMS VERSION: 1.3.5
  • RUBY VERSION: 1.8.7 (2009-06-12 patchlevel 174) [i686-darwin9]
  • INSTALLATION DIRECTORY: /opt/local/lib/ruby/gems/1.8
  • RUBY EXECUTABLE: /opt/local/bin/ruby
  • EXECUTABLE DIRECTORY: /opt/local/bin
  • RUBYGEMS PLATFORMS:
    • ruby
    • x86-darwin-9
  • GEM PATHS:
    • /opt/local/lib/ruby/gems/1.8
    • /Users/pito/.gem/ruby/1.8
  • GEM CONFIGURATION:
  • REMOTE SOURCES:

GEM SPECIFICATION FOR THE GEM IN QUESTION

/opt/local/lib/ruby/gems/1.8$ gem specification wxruby
— !ruby/object:Gem::Specification
name: wxruby
version: !ruby/object:Gem::Version
version: 2.0.0
platform: universal-darwin-9
authors:

  • wxRuby development team
    autorequire:
    bindir: bin
    cert_chain: []

date: 2009-02-26 00:00:00 -05:00
default_executable:
dependencies: []
… much more …

OTHER SHELL ENV

/opt/local/lib/ruby/gems/1.8$ echo $PATH
/opt/local/bin:/opt/local/sbin:/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin

/opt/local/lib/ruby/gems/1.8$ echo $GEMPATH
/opt/local/lib/ruby/gems/1.8
/opt/local/lib/ruby/gems/1.8$

#2

/opt/local/lib/ruby/gems/1.8$ gem which wxruby
Can’t find ruby library file or shared library wxruby
/opt/local/lib/ruby/gems/1.8$

Might be a bug. http://github.com/Pistos/ruby-which/tree/master might
help temporarily.
-r

#3

On Aug 18, 2009, at 08:43, Pito S. wrote:

Installing ri documentation for wxruby-2.0.0-universal-darwin-9…
Installing RDoc documentation for wxruby-2.0.0-universal-darwin-9…
/opt/local/lib/ruby/gems/1.8$ gem which wxruby
Can’t find ruby library file or shared library wxruby
/opt/local/lib/ruby/gems/1.8$

This is not a peculiarity with this particular gem. There are others
in
this odd state too.

Is there even a wxruby in the gem?

gem contents -l wxruby

will tell you if you’ve got the gem installed

You can also check from the .gem file without installing:

$ gem fetch wxruby
Downloaded wxruby-2.0.0-universal-darwin-9
$ gem spec wxruby-2.0.0-universal-darwin-9.gem files | grep lib

  • lib/wx
    […]
  • lib/wx.rb
    […]

Nope.

Try:

require ‘wx’

instead.

Hey look! It’s even described right in the Getting Started tutorial:

http://wxruby.rubyforge.org/wiki/wiki.pl?Getting_Started

Which is linked off the homepage!

$ gem list -dr wxruby

*** REMOTE GEMS ***

wxruby (2.0.0, 1.9.7, 1.9.3, 1.9.2)
Platforms:
1.9.2: i686-darwin8.8.2, powerpc-darwin8.10.0
1.9.3: universal-darwin
1.9.7: i386-mswin32
2.0.0: universal-darwin-9, x86-linux, x86-mingw32, x86-
mswin32-60,
x86_64-linux
Author: wxRuby development team
Rubyforge: http://rubyforge.org/projects/wxruby
Homepage: http://wxruby.org/

 Ruby interface to the wxWidgets GUI library
#4

On Aug 18, 2009, at 11:47, Pito S. wrote:

Which, the way I was running it, led it to look at the ruby that comes
with OSX rather than the one I have designated as primary, which is
actually in /opt/local/…

Designate /opt/local/ruby as your primary ruby by setting your PATH,
then /usr/bin/env can work as designed.

My gem install is going into the primary ruby
install so when the sample app runs, it’s not finding it. So removing
that first line makes the thing work.

$ gem which wxruby
Can’t find ruby library file or shared library wxruby
$

I told you that wxruby doesn’t exist already.

You can use gem contents -l as in my previous mail to see which files
are in a gem to make a guess at what to use. Of course, you should go
read the documentation first if you can’t immediately figure out how
to use the gem.

require ‘rubygems’
rescue LoadError
end
require ‘wx’

Why are you still trying to require a file that doesn’t exist (wxruby)
and that the documentation says doesn’t exist (linked-to from my
previous mail)? The documentation tells you which file to require.
You even found a file that uses the wxruby gem and you’re still
looking for the wrong file…

Not every gem name has a 1:1 mapping to the file you need to require.
When require name_of_gem doesn’t work, you can use the various tools
from my previous email to find the file you need to require. Of
course the first spot you should check is the documentation for the
gem you’re using.

#5

Eric H. wrote:
I don’t think I exactly followed this. But in the meanwhile I think I
have figured out what was tripping me up. The sample apps that come with
wxruby begin with a line that looks like this:

#!/usr/bin/env ruby

wxRuby2 Sample Code. Copyright © 2004-2008 wxRuby development team

Freely reusable code: see SAMPLES-LICENSE.TXT for details

Which, the way I was running it, led it to look at the ruby that comes
with OSX rather than the one I have designated as primary, which is
actually in /opt/local/… My gem install is going into the primary ruby
install so when the sample app runs, it’s not finding it. So removing
that first line makes the thing work.

It still doesn’t explain to me why this is happening, but it might be,
as the first response said, a bug in “gem which”. It’s a bit worrysome,
but for the moment it’s not holding me up:

$ sudo gem install wxruby
Successfully installed wxruby-2.0.0-universal-darwin-9
1 gem installed
Installing ri documentation for wxruby-2.0.0-universal-darwin-9…
Installing RDoc documentation for wxruby-2.0.0-universal-darwin-9…
$ gem which wxruby
Can’t find ruby library file or shared library wxruby
$

By the way, you asked:

Is there even a wxruby in the gem?

The code doesn’t look for it; here’s what it looks like:

#!/usr/bin/env ruby

wxRuby2 Sample Code. Copyright © 2004-2008 wxRuby development team

Freely reusable code: see SAMPLES-LICENSE.TXT for details

begin
require ‘rubygems’
rescue LoadError
end
require ‘wx’

#6

Eric H. wrote:

On Aug 18, 2009, at 11:47, Pito S. wrote:

Which, the way I was running it, led it to look at the ruby that comes
with OSX rather than the one I have designated as primary, which is
actually in /opt/local/…

Designate /opt/local/ruby as your primary ruby by setting your PATH,
then /usr/bin/env can work as designed.

I think that’s how I have it:

$ echo $PATH
/opt/local/bin:/opt/local/sbin:/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin
~$ echo $GEMPATH
/opt/local/lib/ruby/gems/1.8/
~$

My gem install is going into the primary ruby
install so when the sample app runs, it’s not finding it. So removing
that first line makes the thing work.

$ gem which wxruby
Can’t find ruby library file or shared library wxruby
$

I told you that wxruby doesn’t exist already.

You can use gem contents -l as in my previous mail to see which files
are in a gem to make a guess at what to use. Of course, you should go
read the documentation first if you can’t immediately figure out how
to use the gem.

require ‘rubygems’
rescue LoadError
end
require ‘wx’

Why are you still trying to require a file that doesn’t exist (wxruby)
and that the documentation says doesn’t exist (linked-to from my
previous mail)? The documentation tells you which file to require.
You even found a file that uses the wxruby gem and you’re still
looking for the wrong file…

Hm, I thought I was requiring wx.rb which in does exist. I agree that
wxruby does not exist. Am I missing it totally?

However, your reply has helped me also uncover another misunderstanding,
which may be what you were trying to say all along, that is that:

$gem which ‘xxx’
looks for a file called xxx.rb in a gem, rather than a gem called xxx.
That’s why my

$gem which wxruby

Keeps saying that it can’t find it, but now I tried

$gem which wx

and that succeeds.

Not every gem name has a 1:1 mapping to the file you need to require.
When require name_of_gem doesn’t work, you can use the various tools
from my previous email to find the file you need to require. Of
course the first spot you should check is the documentation for the
gem you’re using.

Yeah, that’s a key bit of the puzzle that I hadn’t understood. Thanks!