Q:

Error on "pod install --verbose"

I just installed pod with this command
sudo gem install cocoapods

git cloned a project from git repository and run pod install --verbose and I get this error:

Resolving dependencies of `Podfile`
[!]  Unable to integrate the following embedded targets with their respective host targets (a host target is a "parent" target which embeds a "child" target like a framework or extension):

- MyApp (true) and OneSignalNotificationServiceExtension (false) do not both set use_frameworks!. 

I can't get this app tower inside Xcode because of this.  I get this error message:

update
this is my (the only one) Podfile

update 2
after putting up the use_frameworks!  line I get this:

A:

add use_frameworks!  to solve this problem on OneSignalNotificationServiceExtension. 

target 'OneSignalNotificationServiceExtension' do
  use_frameworks! 
  pod 'OneSignal', '>= 2.5.2', '< 3.0'
end

A:

Okay!   
Looks like the solution in your case was to move use_frameworks!  up and out of a specific target and make it global for the Podfile. 
The issues you're now seeing (in your Update 2) is that you need to go into your Project Settings and fix the ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES setting.   I'd recommend simply removing the build setting.