Swift Version NativeScript

Question

Using NativeScript how can I run a project under iOS? I get these messages when I run tns run iOS --bundle

Webpack compilation complete. Watching for file changes.
Webpack build done!
Copying template files...
Platform ios successfully added. v4.2.0
Executing before-shouldPrepare hook from /Users/Zian/Documents/Projects/NativeScript/Hybrid/hooks/before-shouldPrepare/nativescript-dev-webpack.js
Preparing project...
Executing before-prepareJSApp hook from /Users/Zian/Documents/Projects/NativeScript/Hybrid/hooks/before-prepareJSApp/nativescript-dev-webpack.js
Installing pods...
Analyzing dependencies
Downloading dependencies
Installing Socket.IO-Client-Swift (11.1.3)
Installing StarscreamSocketIO (8.0.7)
Installing Toaster (2.0.4)
[!] Unable to determine Swift version for the following pods:

- `Socket.IO-Client-Swift` does not specify a Swift version and none of the targets (`Hybrid`) integrating it have the `SWIFT_VERSION` attribute set. Please contact the author or set the `SWIFT_VERSION` attribute in at least one of the targets that integrate this pod.
- `StarscreamSocketIO` does not specify a Swift version and none of the targets (`Hybrid`) integrating it have the `SWIFT_VERSION` attribute set. Please contact the author or set the `SWIFT_VERSION` attribute in at least one of the targets that integrate this pod.
- `Toaster` does not specify a Swift version and none of the targets (`Hybrid`) integrating it have the `SWIFT_VERSION` attribute set. Please contact the author or set the `SWIFT_VERSION` attribute in at least one of the targets that integrate this pod.
Unable to apply changes on device: 21FFE2BB-EB0D-48E3-A7AD-28CA08DD21E5. Error is: Command pod failed with exit code 1 Error output: 

[!] Automatically assigning platform `ios` with version `8.0` on target `Hybrid` because no platform was specified. Please specify a platform for this target in your Podfile. See `https://guides.cocoapods.org/syntax/podfile.html#platform`.

Can someone help me out?

Answer 1

Just had these same errors and found out downgrading from cocoapods 1.6.0 to 1.5.3 fixed it for me.

    sudo gem uninstall cocoapods
    sudo gem install cocoapods -v 1.5.3

Answer 2

The problem here seems to be Toaster (2.0.4), which appears to have been developed for Swift 3.

I did this in order to resolve the issue:

1. go to the main folder for the nativescript project

2. In your bash shell, do:

   % export SWIFT_VERSION=3

3. Then do your usual:

   % tns build ios --bundle

4. Then open the project in Xcode:

   % cd platforms/ios

   % Open *.workspace

You'll get a warning about a build error in the pods project and may need to set your development team, but it should work.

Answer 3

The problem is with Cocoapods 1.6.x which have different behavior when it comes up to SWIFT_VERSION. Previously it was possible to set the SWIFT_VERSION in post_install hook of the Podfile, but now the pod install command fails before even getting to post_install. The best solution is to use Cocoapod which already has SWIFT_VERSION set, i.e. in case you face the error, try to contact the Pod author. Meanwhile, as a workaround, you can add a pre_install script in your <path to App_Resources/iOS/Podfile file with the following content:

pre_install do |installer|
    installer.analysis_result.specifications.each do |s|
        if s.name == 'Socket.IO-Client-Swift' || s.name == 'Starscream' || s.name == 'StarscreamSocketIO' || s.name == 'Toaster'
            s.swift_version = '4.2'
        end
    end
end

For each of the Pods you can set different Swift version based on their requirements.

Answer 4

I have it fixed with @K Brown's answer.

Was having these errors when running tns run ios --bundle for Socket.IO-Client-Swift, StarscreamSocketIO and Toaster when both v1.6.0 and v1.5.3 of Cocoapods installed:

- `<package name>` does not specify a Swift version and none of the targets 
(`<project name>`) integrating it have the `SWIFT_VERSION` attribute set. 
Please contact the author or set the `SWIFT_VERSION` attribute in at least one 
of the targets that integrate this pod. 

Below are the commands used:

sudo gem uninstall cocoapods

sudo gem install cocoapods -v 1.5.3

rm -Rf platforms

tns install

tns run ios --bundle

Answer 5

Here is the real fix ! You can't stick with Cocoapods 1.5.3 forever...

Downgrading to 1.5.3 isn't a proper workaround and will not be sustainable in the future. In fact, this error is due to a new behavior introduced in Cocoapods 1.6.0 version, which force developers to set a Swift version to their projects. The goal is in fact to make library developers specify a Swift version in their podspec, so that library users don't have to do this manually (thanks to post_install scripts for example). You can see my discussion about this with a Cocoapods maintainer here. I do agree that this behavior is a bit misleading, as we try to set the Swift version in post_install script but an error is returned before…

In fact, as I have been told by the maintainer, the correct fix to this issue is to set a Swift version at project level (and therefore not at Pod level). To do this, just add a new User Defined Setting in Build Settings, with key SWIFT_VERSION and value 4.0 (for example, as whatever value should work here if you also set the version at Pod level with post_install script).

Long story short, the fix is to add this key/value :

Note that as you're using NativeScript, you may want to set the Swift version by running command export SWIFT_VERSION=4 in your project folder, before building.