Search path for 'nested' .so files

ruby-talk
1

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
2

Actually, I think it’s libruby.so saying that it can’t find
./Dumstr.so. After all, if libruby didn’t run it wouldn’t read your
ruby file.

such file or directory - ./Dumstr.so (LoadError)
from dumstr.rb:3

You need to make sure that Dumstr.so is on one of the libs in your
search path:

/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

···

On Thursday 25 July 2002 06:02 pm, Gray, Jeff wrote:

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?

–
Ned Konz
http://bike-nomad.com
GPG key ID: BEEA7EFE

3

* 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. :^)]

This is bad, try to avoid it.

If you want to make a private version of ruby, compile it with

  ./configure --prefix=/directory/where/you/want/install/it

Then be sure that this private version of ruby is find by the shell when
you call ruby (PATH)

Don't try to mix different versions of ruby

Guy Decoux