Traceback (most recent call last):
31: from /usr/local/bin/pod:23:in `<main>'
30: from /usr/local/bin/pod:23:in `load'
29: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/bin/pod:36:in `<top (required)>'
28: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
27: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
26: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/lib/cocoapods.rb:17:in `<top (required)>'
25: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/lib/cocoapods.rb:74:in `<module:Pod>'
24: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
23: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
22: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/lib/cocoapods/core_overrides.rb:1:in `<top (required)>'
21: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
20: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
19: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/lib/cocoapods/sources_manager.rb:5:in `<top (required)>'
18: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-1.8.4/lib/cocoapods/sources_manager.rb:176:in `<module:Pod>'
17: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
16: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
15: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.8.4/lib/cocoapods-core/trunk_source.rb:1:in `<top (required)>'
14: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.8.4/lib/cocoapods-core/trunk_source.rb:2:in `<module:Pod>'
13: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
12: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
11: from /Library/Ruby/Gems/2.6.0/gems/cocoapods-core-1.8.4/lib/cocoapods-core/cdn_source.rb:3:in `<top (required)>'
10: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
9: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
8: from /Library/Ruby/Gems/2.6.0/gems/concurrent-ruby-1.1.5/lib/concurrent.rb:6:in `<top (required)>'
7: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
6: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
5: from /Library/Ruby/Gems/2.6.0/gems/concurrent-ruby-1.1.5/lib/concurrent/atomics.rb:5:in `<top (required)>'
4: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
3: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
2: from /Library/Ruby/Gems/2.6.0/gems/concurrent-ruby-1.1.5/lib/concurrent/atomic/count_down_latch.rb:2:in `<top (required)>'
1: from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
/System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require': cannot load such file -- concurrent/atomic/java_count_down_latch (LoadError)