Just archiving my work. These can be done using fastlane plugins https://docs.fastlane.tools/actions/version_bump_podspec/#version_bump_podspec https://docs.fastlane.tools/actions/version_get_podspec/#version_get_podspec

Fastlane podspec version utils.rb

lane :replace_podspec_version do |options|
  # Input file (content)  => "s.version = '0.1.0'"
  # Input new_version     => "0.2.0"
  # Output file (content) => "s.version = '0.2.0'"
  # Note: For debugging, you can remove -i to make it print output to console without editing file in place.
  #       Somehow backup file *.bak has to be created for edit in-place (-i) option, otherwise sed command will fail.
  sh("cd ..; sed -i bk \"s/\\(s.version.*['\\\"]\\).*\\(['\\\"]\\)/\\1#{options[:new_version]}\\2/g\" #{options[:file]}")
end

lane :get_podspec_version do |options|
  # Input file (content)  => "s.version = '0.1.0'"
  # Output  => "0.1.0"
  sh("cd ..; pcregrep -o1 \"s.version.*[\\\'\\\"](.*)[\\\'\\\"]\" #{options[:file]}")
end