Open Radar

 
Summary:
In Xcode 8b5, there are numerous errors with the code for the plugin itself and the xcodeproj file when trying to build an Xcode Plugin file. 

Steps to Reproduce:
1. Create new xcode plugin project. 
2. Notice rdar://27841858, switch to secondary scheme
3. Receive error: 

Check dependencies

“Use Legacy Swift Language Version” (SWIFT_VERSION) is required to be configured correctly for targets which use Swift. Use the [Edit > Convert > To Current Swift Syntax…] menu to choose a Swift version or use the Build Settings editor to configure the build setting directly.

4. Update “Use Legacy Swift Language Version” to Yes. Build app. 
5. Receive 2 compiler warnings about use of string literal selectors being deprecated
6. Receive warning about updating your project to recommended project settings, even though you *just* created this project.
7. Receive compiler error about force-unwrapping a non-optional on NSMenu
8. Fix error. Build app. 
9. Receive 2 more compiler warnings about use of var instead of let for items which are never mutated. 


Expected Results:
- Plugin builds out of the box on all schemes without warnings, errors or settings update recommendations
- Plugin template uses non-deprecated syntax
- Plugin uses lets instead of vars where appropriate

Actual Results:
- Plugin won’t build on valid scheme until a value for “Use legacy swift language version” is selected
- Plugin template uses string literal selector syntax instead of #selector syntax
- Plugin template uses vars several places where lets should be used. 

Regression:
Hadn’t tried this in earlier betas because I am a horrendous procrastinator. 

Notes:
I’ve attached a project I’m working on - the INTERPOL.swift file is essentially my suggestion for how the template file should be refactored.