From: "Gray, Jeff" <jeff.gray@...>
Date: 2002-07-26T10:02:49+09:00
Subject: Search path for 'nested' .so files...

I'm making my first foray into the land of C extensions to Ruby and am
having the following problem.  Mind you, I have virtually no practical
experience with developing in C, so my apologies for what is probably a
completely boneheaded question...

The problem is that my compiled C extension gives the following error when
require'd:

dumstr.rb:3:in `require': libruby.so: cannot open shared object file:
  No such file or directory - ./Dumstr.so (LoadError)

Here's the rest of the picture:
* I am using a "private" installation of Ruby 1.6.7 (as opposed to our
  site installation of 1.6.5).  The .so file was compiled using the
  makefile that was produced by a simple extconf.rb, but needed to
  be hacked a bit to get it to find/use the 1.6.7 libruby.so.  This is
  relevant because using the site installation of 1.6.5 for both the
  Makefile generation and execution of the script produces a .so that
  doesn't have a LoadError.  [It just core dumps, which is certainly my
  own fault. :^)]

* I'm running the Ruby script that requires the .so as follows (this is
  on a Linux box):

% cat dumstr.rb
puts $:
require 'Dumstr'

% alias ruby167
/users/jgray/pkgs/ruby/ruby-1.6.7/ruby
-I"/users/jgray/pkgs/ruby/ruby-1.6.7:/users/jgray/pkgs/ruby/ruby-1.6.7/lib"

% ls -l /users/jgray/pkgs/ruby/ruby-1.6.7/lib/libruby.so
-rwxr-xr-x    1 jgray    1636210 Jul 24 12:31
/users/jgray/pkgs/ruby/ruby-1.6.7/lib/libruby.so*

% ls -l ./libruby.so
lrwxrwxrwx    1 jgray         48 Jul 25 17:11 ./libruby.so ->
/users/jgray/pkgs/ruby/ruby-1.6.7/lib/libruby.so*

% ls -l /users/jgray/pkgs/ruby/ruby-1.6.7/ruby
-rwxr-xr-x    1 jgray    1475058 Jun  4 18:29
/users/jgray/pkgs/ruby/ruby-1.6.7/ruby*

% ls -l /users/jgray/pkgs/ruby/ruby-1.6.7/libruby.so
lrwxrwxrwx    1 jgray         14 Jul 25 17:21
/users/jgray/pkgs/ruby/ruby-1.6.7/libruby.so -> lib/libruby.so

% ruby167 dumstr.rb
/users/jgray/pkgs/ruby/ruby-1.6.7
/users/jgray/pkgs/ruby/ruby-1.6.7/lib
/usr/local/lib/ruby/site_ruby/1.6
/usr/local/lib/ruby/site_ruby/1.6/i686-linux
/usr/local/lib/ruby/site_ruby
/usr/local/lib/ruby/1.6
/usr/local/lib/ruby/1.6/i686-linux
.
dumstr.rb:3:in `require': libruby.so: cannot open shared object file: No
such file or directory - ./Dumstr.so (LoadError)
        from dumstr.rb:3


Basically, I'm completely stumped as to why libruby.so can't be found...
it's linked to or resides in three places that are all on the search path,
one of which is the cwd.  What am I doing wrong here?

Thanks,

   - jeff