新计算机和干净的环境
环境：
MacOS (10.14.5)
XCode (11.3)
Gem (3.1.1)
RVM (1.29.9)
Ruby (2.6.3)
终端：
$ sudo gem install -n /usr/local/bin cocoapods // success
$ pod setup // failure
错误信息：
Traceback (most recent call last):
6: from /Users/apple/.rvm/gems/ruby-2.6.3/bin/ruby_executable_hooks:10:in `<main>'
5: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:49:in `run'
4: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:49:in `each'
3: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:50:in `block in run'
2: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/rubygems-bundler-1.4.5/lib/rubygems_executable_plugin.rb:4:in `block in <top (required)>'
1: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:92:in `require'
/Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:92:in `require': cannot load such file -- rubygems-bundler/noexec (LoadError)
10: from /Users/apple/.rvm/gems/ruby-2.6.3/bin/ruby_executable_hooks:10:in `<main>'
9: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:49:in `run'
8: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:49:in `each'
7: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/executable-hooks-1.6.0/lib/executable-hooks/hooks.rb:50:in `block in run'
6: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/rubygems-bundler-1.4.5/lib/rubygems_executable_plugin.rb:4:in `block in <top (required)>'
5: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:156:in `require'
4: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:168:in `rescue in require'
3: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/site_ruby/2.6.0/rubygems/core_ext/kernel_require.rb:168:in `require'
2: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/rubygems-bundler-1.4.5/lib/rubygems-bundler/noexec.rb:131:in `<top (required)>'
1: from /Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/rubygems-bundler-1.4.5/lib/rubygems-bundler/noexec.rb:124:in `check'
/Users/apple/.rvm/rubies/ruby-2.6.3/lib/ruby/gems/2.6.0/gems/rubygems-bundler-1.4.5/lib/rubygems-bundler/noexec.rb:84:in `setup': undefined method `plain_specs' for #<Bundler::RubygemsIntegration:0x00007f8db60194b0> (NoMethodError)
请问是什么问题？如何处理？