please add .ruby-version support

[mpapis]

Hi,

@fnichol come with very nice idea to support one project file that could be used by all the ruby managers/switchers.

rbfu and RVM already support it, could you add it to rbenv too ?

Thanks,
Michal

[fnichol]

I'm more than happy to write up a pull request or a candidate implementation. Best case is it's about an additional 3-4 lines code code. I'm mostly curious if this is an idea with merit or if I've missed the boat. Thanks as always!

[tpope]

+1. Providing a tool-agnostic way to specify the version would help reduce the choice of tool from a holy war to a personal preference.

[ghost]

This is definitely of merit. If we all work together for a bit of unification and forget the bravado, pissing contests, and holy wars we might actually be able to help the ruby community!

[fesplugas]

+1

"Your .rbenv-version or .rvmrc file is an important piece of documentation."

[michaelklishin]

This is a very good idea.

[stjernstrom]

+1

Maybe the easiest way is just to drop support for .rbenv-version and use .ruby-version instead?

[pusewicz]

+1

[hmans]

Definitely 👍 for .ruby-version. No opinion on dropping support for .rbenv-version (or .rbfu-version), really. Removing support for those files would probably surprise a lot of people. :)

[mpapis]

any progress on merging #201 ?

[rmm5t]

Bundler 1.2 is going to support a ruby version declaration in your Gemfile. Heroku is already supporting it.

[fnichol]

The bundler support is going to be great on Heroku and possibly good with RVM but I don't see how that attribute can be used out-of-the-box with rbenv. The build pack calls bundle platform --path to get the resulting string, but that string will not support the patch level. Unless you install your own Ruby builds under versions/, use symlinks, or create your own ruby-build definitions rbenv isn't going to know what version you want.

I'd imagine that in a Gemfile you could get away with:

ruby IO.read('.ruby-version').chomp.sub(/-p.*$/, '')

Having said all that, I'm happy to help 😄

[rmm5t]

@fnichol Good idea on having the Gemfile read the .ruby-version or .rbenv-version file. That works well even on Heroku. I went with something like this to ensure that the file can be found no matter where bundler is executed from:

def ruby_version(file = ".rbenv-version")
  file = File.join(File.dirname(__FILE__), file)
  IO.read(file).chomp.sub(/-p.*$/, "")
end

ruby ruby_version

[elia]

👍

[jarl-dk]

👍

[mislav]

@sstephenson I've looked into .ruby-version file feature can be implemented via plugin but it's not possible without overriding (and thus repeating the logic for) the whole rbenv-local command. I'm interested in at least enabling hook support for this. I'm interested in your opinion in any of these options:

1. Add support for reading the .ruby-version file similar to that in Adds support for .ruby-version files #201. The string "ruby-" would be stripped from the resulting value to enable compatibility with MRI.
2. Add a hook. Not sure if this is a good place to introduce a hook because of possible slowdown?

[mislav]

We want to support reading from .ruby-version files in the current release. I've started work to do that in #300

[sstephenson]

#302