I get a collision of results for the hash method of arrays : ruby 1.9.3, arm A9, debian sid.

bundle_env.txt

Bundler 1.3.5
Ruby 1.9.3 (2013-06-27 patchlevel 448) [arm-linux-eabihf]
Rubygems 1.8.23
GEM_HOME 
rubygems-bundler (1.4.2)

Bundler settings
  bin
    Set for your local app (/home/prahal/Projects/Work/Wimake/KeyBox/alban/test2/.bundle/config): "bin"


Gemfile
# Update this Gemfile with any additional dependencies and run
# 'bundle install' to get them all installed. Daemon-kit's capistrano
# deployment will ensure that the bundle required by your daemon is properly
# installed.
#
# For more information on bundler, please visit http://gembundler.com

source 'https://rubygems.org'


gem 'serialport', "~> 1.2.1"
gem 'sqlite3'
gem 'sequel'

# Live on the edge instead: gem 'daemon-kit', :github => 'kennethkalmer/daemon-kit'
gem 'daemon-kit'
gem 'eventmachine'
#
# safely (http://github.com/kennethkalmer/safely)
gem 'safely' # Optional, but recommended.

# gem 'toadhopper' # For reporting exceptions to hoptoad
# gem 'mail' # For reporting exceptions via mail


gem 'amqp'
group :development, :test do
  gem 'rake'
  gem 'rspec'
  # fake http
  gem "fakeweb", "~> 1.3"
  # Fixtures
  gem 'sequel-fixture'
  # fabrics
  gem 'fabrication'
  # BDD
  gem 'aruba'
  gem 'cucumber'
end


Gemfile.lock
GEM
  remote: https://rubygems.org/
  specs:
    activesupport (3.1.12)
      multi_json (~> 1.0)
    amq-protocol (1.8.0)
    amqp (1.1.1)
      amq-protocol (>= 1.8.0)
      eventmachine
    aruba (0.5.3)
      childprocess (>= 0.3.6)
      cucumber (>= 1.1.1)
      rspec-expectations (>= 2.7.0)
    axiom-types (0.0.5)
      descendants_tracker (~> 0.0.1)
      ice_nine (~> 0.9)
    backports (3.3.5)
    builder (3.2.2)
    childprocess (0.3.9)
      ffi (~> 1.0, >= 1.0.11)
    coercible (0.2.0)
      backports (~> 3.0, >= 3.1.0)
      descendants_tracker (~> 0.0.1)
    cucumber (1.3.10)
      builder (>= 2.1.2)
      diff-lcs (>= 1.1.3)
      gherkin (~> 2.12)
      multi_json (>= 1.7.5, < 2.0)
      multi_test (>= 0.0.2)
    daemon-kit (0.2.3)
      eventmachine (>= 0.12.10)
      i18n
      rubigen
      safely (>= 0.3.1)
      thor
    descendants_tracker (0.0.3)
    diff-lcs (1.2.5)
    discoverer (0.0.2)
      virtus
    equalizer (0.0.7)
    eventmachine (1.0.3)
    fabrication (2.9.3)
    fakeweb (1.3.0)
    fast (0.1.4)
      metafun (>= 0.2.0)
      sub-setter (>= 0.0.2)
    ffi (1.9.3)
    gherkin (2.12.2)
      multi_json (~> 1.3)
    i18n (0.6.5)
    ice_nine (0.10.0)
    metafun (0.2.0)
    multi_json (1.8.2)
    multi_test (0.0.2)
    rake (10.1.0)
    rspec (2.14.1)
      rspec-core (~> 2.14.0)
      rspec-expectations (~> 2.14.0)
      rspec-mocks (~> 2.14.0)
    rspec-core (2.14.7)
    rspec-expectations (2.14.4)
      diff-lcs (>= 1.1.3, < 2.0)
    rspec-mocks (2.14.4)
    rubigen (1.5.8)
      activesupport (>= 2.3.5, < 3.2.0)
    safely (0.3.2)
    sequel (4.4.0)
    sequel-fixture (2.0.1)
      fast
      sequel
      symbolmatrix
    serialport (1.2.3)
    sqlite3 (1.3.8)
    sub-setter (0.0.2)
    symbolmatrix (1.2.0)
      discoverer
    thor (0.18.1)
    virtus (1.0.0)
      axiom-types (~> 0.0.5)
      coercible (~> 0.2)
      descendants_tracker (~> 0.0.1)
      equalizer (~> 0.0.7)

PLATFORMS
  ruby

DEPENDENCIES
  amqp
  aruba
  cucumber
  daemon-kit
  eventmachine
  fabrication
  fakeweb (~> 1.3)
  rake
  rspec
  safely
  sequel
  sequel-fixture
  serialport (~> 1.2.1)
  sqlite3

collision.rb

# on arm (odroid u2)
#$ ruby ~/collision.rb
#708079652
#708079652

require 'rubygems'

p ["discoverer", Gem::Version.new("0.0.2"), "ruby"].hash
p ["sub-setter", Gem::Version.new("0.0.2"), "ruby"].hash

issue.txt

I am attempting to run rspec inside my project and even my own project but fails bundler. Backtrace is:
$ rspec
including Virtus module is deprecated. Use 'include Virtus.model' instead /var/lib/gems/1.9.1/gems/discoverer-0.0.2/lib/discoverer/model.rb:4:in `include'
/var/lib/gems/1.9.1/gems/backports-3.3.5/lib/backports/tools.rb:328:in `require': cannot load such file -- sub-setter (LoadError)
        from /var/lib/gems/1.9.1/gems/backports-3.3.5/lib/backports/tools.rb:328:in `require_with_backports'
        from /var/lib/gems/1.9.1/gems/fast-0.1.4/lib/fast.rb:2:in `<top (required)>'
        from /var/lib/gems/1.9.1/gems/backports-3.3.5/lib/backports/tools.rb:328:in `require'
        from /var/lib/gems/1.9.1/gems/backports-3.3.5/lib/backports/tools.rb:328:in `require_with_backports'
        from /var/lib/gems/1.9.1/gems/sequel-fixture-2.0.1/lib/sequel-fixture.rb:3:in `<top (required)>'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:72:in `require'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:72:in `block (2 levels) in require'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:70:in `each'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:70:in `block in require'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:59:in `each'
        from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:59:in `require'
        from /usr/lib/ruby/vendor_ruby/bundler.rb:132:in `require'
        from /home/prahal/Projects/Work/Wimake/KeyBox/alban/test2/config/environment.rb:10:in `<top (required)>'
        from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
        from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
        from /home/prahal/Projects/Work/Wimake/KeyBox/alban/test2/spec/spec_helper.rb:10:in `<top (required)>'
        from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
        from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
        from /home/prahal/Projects/Work/Wimake/KeyBox/alban/test2/spec/test2_spec.rb:1:in `<top (required)>'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `load'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `block in load_spec_files'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `each'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/configuration.rb:896:in `load_spec_files'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/command_line.rb:22:in `run'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:80:in `run'
        from /var/lib/gems/1.9.1/gems/rspec-core-2.14.7/lib/rspec/core/runner.rb:17:in `block in autorun'

It turns out that the sub-setter is partially removed from the Gemfile.lock in the process ! That is it stays as a dependency
of fast, but is removed from the four spaces level (in the "GEM\n specs:" section).
Then one have to do anew "bundle update" to refresh the lock file and get it anew. This matter for to test the "patch" I came up with is working.

It turns out that as above above collision.rb showcase I get the same identifier for two different gems.


Patch in the lazy_specification.rb.diff sort out the issue (but only after a 'bundle update' to restore the Gemfile.lock into
a sane state). I append the gem name to the identifier.
Thus now the keys that are the LazySpecification identifier the LockfileParser @specs hash ought not to overlap (and a gem get discarded as not assignement happens to the specs if the key is already assigned to).

https://github.com/bundler/bundler/blob/master/lib/bundler/lockfile_parser.rb#L128, where identifier comes from https://github.com/bundler/bundler/blob/master/lib/bundler/lazy_specification.rb#L65

lazy_specification.rb.diff

--- lazy_specification.rb.old   2013-11-21 00:34:10.071335635 +0100
+++ lazy_specification.rb       2013-11-21 00:33:29.426644500 +0100
@@ -61,7 +61,7 @@
     end
 
     def identifier
-      @__identifier ||= [name, version, source, platform, dependencies].hash
+      @__identifier ||= [name, version, source, platform, dependencies].hash.to_s + name
     end
 
   private