Ensure binstubs generated when using --standalone point to the standalonde bundle

[cowboyd]

The binstubs generated by Bundler currently require both rubygems and bundler to be installed in order to execute: requirements not guaranteed at runtime for a standalone bundle.

This introduces a separate method to generate binstubs when generating a standalone bundle. It first adds the root of the standalone to the load path, and then requiring bundler/setup from there.

I was on the fence whether to leave the load path alone and load bundler/setup.rb directly via its path relative to the generated executeable, but in the end decided to go the way I did so that application code requiring 'bundler/setup' will continue to function.

I'm pretty excited about the standalone feature, and I hope that this makes it into 1.1

[indirect]

Thanks for the patch! We're feature-frozen for 1.1 right now, but the standalone feature is part of the 1.1 release. This patch seems it's a bug fix for binstubs with standalone, so I'm inclined to pull it for the next 1.1 RC.

[cowboyd]

I agree. The standalone binstubs are pretty broken without this. They'll either raise an error, or perhaps even worse, load code from the wrong place.

[cowboyd]

I just spotted a bug in that the standalone binstub assumes that it's being run from the directory above bin

If you could hold off merging until I can update the spec and fix it, I'd appreciate it. This will be tomorrow morning. Thanks!

[hone]

sure. thanks for the help @cowboyd

[cowboyd]

Ok, binstubs are callable from within any directory, and the real binary will be loaded relative to the stub file.

[hone]

Thanks so much for fixing this.