jruby-head and bundler: There was an error parsing `Gemfile` etc

gistfile1.txt

Having a bit of a time wrangling latest jruby with Bundler.

Here's a failed build, with DEBUG=1 enabled, the stacktrace is below:

  https://travis-ci.org/skywinder/github-changelog-generator/jobs/199707018

I have more of the same in other projects.

- I have no trouble with jruby-9.1.7.0. jruby-head fails.
- I have the same troubles with 1.13.7 on jruby-head.

A compare view of jruby-9.1.7.0 with current master, to see the commits
https://github.com/jruby/jruby/compare/68056ae555a48891a6745bbc9056c6bbc4a14e4c...master



Here is the stacktrace output:

[!] There was an error parsing `Gemfile`: 
[!] There was an error while loading `github_changelog_generator.gemspec`: . Bundler cannot continue.
. Bundler cannot continue.
 #  from /home/travis/build/skywinder/github-changelog-generator/Gemfile:6
 #  -------------------------------------------
 #  
 >  gemspec
 #  
 #  -------------------------------------------
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:479:in `eval_gemspec'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:419:in `block in load_gemspec_uncached'
org/jruby/RubyDir.java:323:in `chdir'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/shared_helpers.rb:55:in `block in chdir'
/home/travis/.rvm/rubies/jruby-head/lib/ruby/stdlib/monitor.rb:214:in `mon_synchronize'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/shared_helpers.rb:54:in `chdir'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:414:in `load_gemspec_uncached'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:404:in `load_gemspec'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/dsl.rb:60:in `block in gemspec'
org/jruby/RubyArray.java:2485:in `map'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/dsl.rb:60:in `gemspec'
/home/travis/build/skywinder/github-changelog-generator/Gemfile:6:in `<eval>'
org/jruby/RubyBasicObject.java:1705:in `instance_eval'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/dsl.rb:41:in `eval_gemfile'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/dsl.rb:11:in `evaluate'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/definition.rb:33:in `build'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:128:in `definition'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler.rb:94:in `setup'
/home/travis/.rvm/gems/jruby-head/gems/bundler-1.14.3/lib/bundler/setup.rb:10:in `<main>'
org/jruby/RubyKernel.java:961:in `require'
/home/travis/.rvm/rubies/jruby-head/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:1:in `(root)'