Gemfile specifying ruby "2.0.0" cannot contain Ruby 2.0 syntax.

[pda]

Ruby 2.0 syntax e.g. %i{list of symbols} is not supported in Gemfiles, even if they specify ruby "2.0.0".

The resulting error Invalid RUBY_VERSION specified is misleading.

If the Gemfile can be detected and parsed as Ruby 2.0, that'd be great.
Short of that, a more correct error message would help.

Example Gemfile:

source "https://rubygems.org"
ruby "2.0.0"
gem "dotenv-rails", groups: %i{development test}

Buildpack output:

-----> Ruby/Rails app detected
 !
 !     Invalid RUBY_VERSION specified: Gemfile-syntax-error:-groups:-%i{development-test}-^-/tmp/build_redacted/Gemfile:20:-syntax-error,-unexpected-$end-groups:-%i{development-test}-^
 !     Valid versions: ruby-2.0.0, ruby-1.9.3, ruby-1.9.2, ruby-1.8.7, ruby-1.9.3-jruby-1.7.0, ruby-1.8.7-jruby-1.7.0, ruby-1.9.3-jruby-1.7.1, ruby-1.8.7-jruby-1.7.1, ruby-1.9.3-rbx-2.0.0dev, ruby-1.8.7-rbx-2.0.0dev
 !
 !     Heroku push rejected, failed to compile Ruby/Rails app

[schneems]

To read your Gemfile we need to have ruby on the system, before we can know what version of ruby you've got declared we have to read your Gemfile. Currently this is done with system ruby which is 1.9.2.

Thanks for reporting the issue, unfortunately no fix for this right now comes to mind. Will keep open to evaluate options.

[pda]

No worries.
Obviously the ideal place to land is processing the Gemfile with Ruby 2.0, providing support for 1.8, 1.9, 2.0 Gemfiles.
I imagine there's a whole lot of yaks between the current situation and that one.

[pda]

Is this problem fixed by Ruby 2.0.0 Now Default on All New Ruby Applications?
That post doesn't specifically mention Ruby 2.0 in the build environment, but it would stand to reason…

[hone]

Sadly, not yet :(. We're still on 1.9.2 in the build environment. The only way to fix this would be to use ruby 2.0.0 in the build environment or move to something like .ruby-version like #63.

[schneems]

Going to put this in the "won't fix" category. It won't change easily or any time soon.