Added bundler as default gems. Revisit [Feature #12733]

* bin/*, lib/bundler/*, lib/bundler.rb, spec/bundler, man/*:
    Merge from latest stable branch of bundler/bundler repository and
    added workaround patches. I will backport them into upstream.
  * common.mk, defs/gmake.mk: Added `test-bundler` task for test suite
    of bundler.
  * tool/sync_default_gems.rb: Added sync task for bundler.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65509 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

man/bundle-exec.1.txt

@@ -0,0 +1,178 @@
+BUNDLE-EXEC(1)							BUNDLE-EXEC(1)
+
+
+
+1mNAME0m
+       1mbundle-exec 22m- Execute a command in the context of the bundle
+
+1mSYNOPSIS0m
+       1mbundle exec 22m[--keep-file-descriptors] 4mcommand0m
+
+1mDESCRIPTION0m
+       This  command  executes	the  command, making all gems specified in the
+       [1mGemfile(5)22m][Gemfile(5)] available to 1mrequire 22min Ruby programs.
+
+       Essentially, if you  would  normally  have  run	something  like  1mrspec0m
+       1mspec/my_spec.rb22m,  and  you	want to use the gems specified in the [1mGem-0m
+       1mfile(5)22m][Gemfile(5)]  and  installed   via	 bundle   install(1)   4mbun-0m
+       4mdle-install.1.html24m, you should run 1mbundle exec rspec spec/my_spec.rb22m.
+
+       Note  that 1mbundle exec 22mdoes not require that an executable is available
+       on your shell's 1m$PATH22m.
+
+1mOPTIONS0m
+       1m--keep-file-descriptors0m
+	      Exec in Ruby 2.0 began discarding non-standard file descriptors.
+	      When  this flag is passed, exec will revert to the 1.9 behaviour
+	      of passing all file descriptors to the new process.
+
+1mBUNDLE INSTALL --BINSTUBS0m
+       If  you	use  the   1m--binstubs   22mflag   in	 bundle   install(1)   4mbun-0m
+       4mdle-install.1.html24m,  Bundler  will	automatically  create  a  directory
+       (which defaults to 1mapp_root/bin22m)  containing  all  of  the	executables
+       available from gems in the bundle.
+
+       After  using 1m--binstubs22m, 1mbin/rspec spec/my_spec.rb 22mis identical to 1mbun-0m
+       1mdle exec rspec spec/my_spec.rb22m.
+
+1mENVIRONMENT MODIFICATIONS0m
+       1mbundle exec 22mmakes a number of changes to the  shell  environment,  then
+       executes the command you specify in full.
+
+       o   make  sure  that  it's  still  possible to shell out to 1mbundle 22mfrom
+	   inside a command invoked by 1mbundle exec 22m(using 1m$BUNDLE_BIN_PATH22m)
+
+       o   put	the  directory	containing  executables  (like	1mrails22m,  1mrspec22m,
+	   1mrackup22m) for your bundle on 1m$PATH0m
+
+       o   make  sure  that if bundler is invoked in the subshell, it uses the
+	   same 1mGemfile 22m(by setting 1mBUNDLE_GEMFILE22m)
+
+       o   add 1m-rbundler/setup 22mto 1m$RUBYOPT22m, which makes sure	that  Ruby  pro-
+	   grams invoked in the subshell can see the gems in the bundle
+
+
+
+       It also modifies Rubygems:
+
+       o   disallow loading additional gems not in the bundle
+
+       o   modify  the 1mgem 22mmethod to be a no-op if a gem matching the require-
+	   ments is in the bundle, and to raise a 1mGem::LoadError 22mif it's not
+
+       o   Define 1mGem.refresh 22mto be a no-op, since the source index is  always
+	   frozen  when  using	bundler,  and  to prevent gems from the system
+	   leaking into the environment
+
+       o   Override 1mGem.bin_path 22mto use the gems in the bundle, making  system
+	   executables work
+
+       o   Add all gems in the bundle into Gem.loaded_specs
+
+
+
+       Finally, 1mbundle exec 22malso implicitly modifies 1mGemfile.lock 22mif the lock-
+       file and the Gemfile do not match. Bundler needs the Gemfile to	deter-
+       mine  things  such as a gem's groups, 1mautorequire22m, and platforms, etc.,
+       and that information isn't stored in  the  lockfile.  The  Gemfile  and
+       lockfile must be synced in order to 1mbundle exec 22msuccessfully, so 1mbundle0m
+       1mexec 22mupdates the lockfile beforehand.
+
+   1mLoading0m
+       By default, when attempting to 1mbundle exec 22mto a file with a  ruby  she-
+       bang,  Bundler will 1mKernel.load 22mthat file instead of using 1mKernel.exec22m.
+       For the vast majority of cases, this is a performance improvement. In a
+       rare  few  cases,  this	could  cause some subtle side-effects (such as
+       dependence on the exact contents of 1m$0 22mor 1m__FILE__22m) and  the  optimiza-
+       tion can be disabled by enabling the 1mdisable_exec_load 22msetting.
+
+   1mShelling out0m
+       Any  Ruby  code that opens a subshell (like 1msystem22m, backticks, or 1m%x{}22m)
+       will automatically use the current Bundler environment. If you need  to
+       shell  out  to  a Ruby command that is not part of your current bundle,
+       use the 1mwith_clean_env 22mmethod  with  a  block.  Any  subshells  created
+       inside  the  block will be given the environment present before Bundler
+       was activated. For example, Homebrew commands run Ruby, but don't  work
+       inside a bundle:
+
+
+
+	   Bundler.with_clean_env do
+	     `brew install wget`
+	   end
+
+
+
+       Using  1mwith_clean_env	22mis  also  necessary if you are shelling out to a
+       different bundle. Any Bundler commands run in a subshell  will  inherit
+       the  current  Gemfile, so commands that need to run in the context of a
+       different bundle also need to use 1mwith_clean_env22m.
+
+
+
+	   Bundler.with_clean_env do
+	     Dir.chdir "/other/bundler/project" do
+	       `bundle exec ./script`
+	     end
+	   end
+
+
+
+       Bundler provides convenience helpers that wrap  1msystem  22mand  1mexec22m,  and
+       they can be used like this:
+
+
+
+	   Bundler.clean_system('brew install wget')
+	   Bundler.clean_exec('brew install wget')
+
+
+
+1mRUBYGEMS PLUGINS0m
+       At  present,  the  Rubygems  plugin  system  requires  all  files named
+       1mrubygems_plugin.rb 22mon the load path of 4many24m installed gem when any  Ruby
+       code requires 1mrubygems.rb22m. This includes executables installed into the
+       system, like 1mrails22m, 1mrackup22m, and 1mrspec22m.
+
+       Since Rubygems plugins can contain arbitrary Ruby code,	they  commonly
+       end up activating themselves or their dependencies.
+
+       For  instance,  the 1mgemcutter 0.5 22mgem depended on 1mjson_pure22m. If you had
+       that version of gemcutter installed (even if you 4malso24m had a newer  ver-
+       sion  without  this problem), Rubygems would activate 1mgemcutter 0.5 22mand
+       1mjson_pure <latest>22m.
+
+       If your Gemfile(5) also contained 1mjson_pure 22m(or a gem with a dependency
+       on  1mjson_pure22m),  the  latest version on your system might conflict with
+       the version in your Gemfile(5), or the snapshot version	in  your  1mGem-0m
+       1mfile.lock22m.
+
+       If this happens, bundler will say:
+
+
+
+	   You have already activated json_pure 1.4.6 but your Gemfile
+	   requires json_pure 1.4.3. Consider using bundle exec.
+
+
+
+       In  this  situation, you almost certainly want to remove the underlying
+       gem with the problematic gem plugin. In general, the authors  of  these
+       plugins	(in this case, the 1mgemcutter 22mgem) have released newer versions
+       that are more careful in their plugins.
+
+       You can find a list of all the gems containing gem plugins by running
+
+
+
+	   ruby -rubygems -e "puts Gem.find_files('rubygems_plugin.rb')"
+
+
+
+       At the very least, you should remove all but the newest version of each
+       gem  plugin, and also remove all gem plugins that you aren't using (1mgem0m
+       1muninstall gem_name22m).
+
+
+
+				 October 2018			BUNDLE-EXEC(1)