Remove pessimistic versioning in gem command output

Switch examples to use `>=2` instead of `~>2.0.0` (which is really
terrible as you are limited to 2.0.x versions).

For the help output, show a simpler example with a single version
restriction, before an example with multiple version restrictions.

Author: jeremyevans

lib/rubygems/commands/fetch_command.rb

@@ -56,7 +56,7 @@ def check_version # :nodoc:
     if options[:version] != Gem::Requirement.default &&
        get_all_gem_names.size > 1
       alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
-                  " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+                  " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:>=2'`"
       terminate_interaction 1
     end
   end

lib/rubygems/commands/help_command.rb

@@ -90,7 +90,9 @@ class Gem::Commands::HelpCommand < Gem::Command
 
 To depend on a specific set of versions:
 
-  gem 'rake', '~> 10.3', '>= 10.3.2'
+  gem 'rake', '>= 10.3.2'
+  # or for multiple version restrictions
+  gem 'rake', '>= 10.3.2', "< 13"
 
 RubyGems will require the gem name when activating the gem using
 the RUBYGEMS_GEMDEPS environment variable or Gem::use_gemdeps.  Use the

lib/rubygems/commands/install_command.rb

@@ -140,7 +140,7 @@ def check_version # :nodoc:
     if options[:version] != Gem::Requirement.default &&
        get_all_gem_names.size > 1
       alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
-                  " version requirements using `gem install 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+                  " version requirements using `gem install 'my_gem:1.0.0' 'my_other_gem:>=2'`"
       terminate_interaction 1
     end
   end

lib/rubygems/commands/uninstall_command.rb

@@ -117,7 +117,7 @@ def check_version # :nodoc:
     if options[:version] != Gem::Requirement.default &&
        get_all_gem_names.size > 1
       alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
-                  " version requirements using `gem uninstall 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+                  " version requirements using `gem uninstall 'my_gem:1.0.0' 'my_other_gem:>=2'`"
       terminate_interaction 1
     end
   end

test/rubygems/test_gem_commands_fetch_command.rb

@@ -157,7 +157,7 @@ def test_execute_two_version
     execute_with_term_error
 
     msg = "ERROR:  Can't use --version with multiple gems. You can specify multiple gems with" \
-      " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+      " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:>=2'`"
 
     assert_empty @ui.output
     assert_equal msg, @ui.error.chomp

test/rubygems/test_gem_commands_install_command.rb

@@ -880,7 +880,7 @@ def test_execute_two_version
     assert_empty @cmd.installed_specs
 
     msg = "ERROR:  Can't use --version with multiple gems. You can specify multiple gems with" \
-      " version requirements using `gem install 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+      " version requirements using `gem install 'my_gem:1.0.0' 'my_other_gem:>=2'`"
 
     assert_empty @ui.output
     assert_equal msg, @ui.error.chomp

test/rubygems/test_gem_commands_uninstall_command.rb

@@ -513,7 +513,7 @@ def test_execute_two_version
     end
 
     msg = "ERROR:  Can't use --version with multiple gems. You can specify multiple gems with" \
-      " version requirements using `gem uninstall 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+      " version requirements using `gem uninstall 'my_gem:1.0.0' 'my_other_gem:>=2'`"
 
     assert_empty @ui.output
     assert_equal msg, @ui.error.lines.last.chomp