How to set the Legacy Swift Versions for each Pod in Podfile

I found this while searching how to set the SWIFT_VERSION to 3.2 for Xcode 9.

Using the AirMapSDK which itself and multiple dependencies need 3.2 instead of 4.0 Here is an example of how to set pod specific SWIFT_VERSION for others that may come across this question.

post_install do |installer|  installer.pods_project.targets.each do |target|    if ['AirMapSDK', 'PhoneNumberKit', 'Lock', 'RxSwift', 'RxSwiftExt', 'RxCocoa', 'RxDataSources', 'ProtocolBuffers-Swift'].include? target.name      target.build_configurations.each do |config|        config.build_settings['SWIFT_VERSION'] = '3.2'      end    end  endend

You can change the if array to specify whatever pod you need to set the version too.

If you need to manage multiple Swift versions for pods, you can build a mapping.

DEFAULT_SWIFT_VERSION = '4'POD_SWIFT_VERSION_MAP = {  'Dotzu' => '3'}post_install do |installer|  installer.pods_project.targets.each do |target|    swift_version = POD_SWIFT_VERSION_MAP[target.name] || DEFAULT_SWIFT_VERSION    puts "Setting #{target.name} Swift version to #{swift_version}"    target.build_configurations.each do |config|      config.build_settings['SWIFT_VERSION'] = swift_version    end  endend

Details

• CocoaPods v1.6.1
• Xcode 10.2.1 (10E1001)

Ruby code in podfile

swift_versions_of_pods = { 'swiftScan' => '4.0', 'GRDB.swift' => '4.2' }post_install do |installer|  installer.pods_project.targets.each do |target|    defined_swift_version = swift_versions_of_pods[target.name]    next if defined_swift_version.blank?    target.build_configurations.each do |config|      config.build_settings['SWIFT_VERSION'] = defined_swift_version    end  endend