Does not compile for any target because of unavailable SFSafariViewController

[kisileno]

On macOS 10.13.1 Beta
Xcode 9.0 (9A235)
AppAuth 0.9.1
Project does not compile because of 'SFSafariViewController' is only available on iOS 9.0 or newer

Changing target from iOS 9 to 10, or 11 does nothing.
Most probably the problem is in Xcode, but anyway, any hints how to fix this?

[ened]

Using Cocoapods?

Based on this SO post: https://stackoverflow.com/a/37289688/375209

Add to the end of your Podfile:

post_install do |installer|
    installer.pods_project.targets.each do |target|
        if "#{target}" == "AppAuth"
            target.build_configurations.each do |config|
                config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.3'
            end
        end
    end
end

:-}

[kisileno]

@ened Thank you!
That fixed the problem. Now my app is compiling and running fine.
But I am a bit concerned about 'IPHONEOS_DEPLOYMENT_TARGET'. Is it a right approach to set target iOS?

Btw all this time I had this in my Podfile:

target 'my app' do
  platform :ios, '10.0'
  pod 'GTMAppAuth'
...

but seems like pods are special and require additional configuration.

[ened]

Either this projects platform dependency should be updated in the podspec or the code should be adapted to support both the old and new method (SFSafari.. being the new one). The method above does the first thing, but limited to your project.

Probably good idea to send a PR here and fix it permanently.

[WilliamDenniss]

So this was a case of a newly introduced warning breaking downstream builds due to our "treat warnings as errors" flag. The code in this case was still functionally correct, but not in a way that would avoid the warning.

Changing the deployment target to 9 is a valid workaround as long as you don't need to target iOS 7 or 8 (which AppAuth still supports). Another workaround is adding silent_warnings! to your Podfile to suppress warnings from all Pods.

#158 resolves the underlying warning, and also moves "treat warnings as errors" from the Podspec to the CI spec. This way warnings will still be flagged during CI, but will avoid breaking downstream builds.