[ruby-core:38952] Re: Init_prelude gone in 1.9.3

On Aug 10, 2011, at 1:18 AM, Christoph Kappel wrote:
> On Wed, Aug 10, 2011 at 09:30, Eric Hodel <[e-mail]> wrote:
>> Set the GEM_HOME and GEM_PATH environment variables.
> 
> So that means I need to populate both env variables myself?

It depends upon the behavior you want.  This is the easiest way.  If you want to use only your own gems, yes, populate both yourself.

> On Wed, Aug 10, 2011 at 00:48, Shugo Maeda <[e-mail]> wrote:
> 
>> In Ruby 1.9.3 the gcc option -fvisibility=hidden is used, so not only
>> Init_prelude() but other many symbols are hidden in 1.9.3.
>> This change was done at r28709, but I haven't seen discussion about it.
>> 
>> I asked the same question about Init_prelude() to nobu yesterday.  He
>> said that ruby_options(2, {"ruby", "-e;"}) can be used instead of
>> Init_prelude() as a workaround.
> 
> So basically another workaround for a workaround, calling Init_prelude
> was a mere hack for me to populate the gam paths.
> 
> I still wonder, why there is no sane way to do that. Even if ruby
> wasn't designed for embedding, why making it even more difficult?


I've never tried to embed ruby so maybe I don't understand the difficulty you're facing.

In order to change the gem paths in ruby (not embedded) you either set GEM_HOME and GEM_PATH through environment variables before ruby has started or you set the path through Gem.paths= in your application.  There isn't a way to set the default paths through C code.

You could probably also use lib/rubygems/operating_system.rb.  See "RubyGems Defaults, Packaging" in `ri Gem`, but that's not really through C code either.