Cocoapods installing error mkmf.rb can't find header files for ruby

Question

sudo gem install cocoapods throws mkmf.rb can't find header files for ruby.

The full output:

Last login: Sat Mar 21 19:00:12 on ttys000
praneeths-MacBook-Air:~ praneeth$ sudo gem install cocoapods
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing cocoapods:
    ERROR: Failed to build gem native extension.

    current directory: /Library/Ruby/Gems/2.3.0/gems/ffi-1.12.2/ext/ffi_c
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby -r ./siteconf20200321-2325-4gn5jh.rb extconf.rb
mkmf.rb can't find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /Library/Ruby/Gems/2.3.0/gems/ffi-1.12.2 for inspection.
Results logged to /Library/Ruby/Gems/2.3.0/extensions/universal-darwin-18/2.3.0/ffi-1.12.2/gem_make.out

Answer 1

This also happened to me and it is because you have to update your ruby version. Someone already posted an issue on cocoapods github repository. That issue pointed me to this stackoverflow answer and this is the solution copy-pasted from that answer:

Open Terminal

curl -L https://get.rvm.io | bash -s stable

Close and Reopen Terminal

rvm install ruby-2.6

rvm use ruby-2.6.5

rvm --default use 2.6.5

From MahmoudKhaled's comment on link