Support for Xcode 12 beta

[Amine Bensalah]

Can't install xcodegen I have a issue with Spectre

==> make install PREFIX=/usr/local/Cellar/xcodegen/2.16.0
Last 15 lines from /Users/amine/Library/Logs/Homebrew/xcodegen/01.make:
[13/18] Compiling PathKit PathKit.swift
[14/19] Compiling Spectre Case.swift
/private/tmp/xcodegen-20200717-5913-n8cz13/XcodeGen-2.16.0/.build/checkouts/Spectre/Sources/Spectre/XCTest.swift:35:14: error: 'recordFailure(withDescription:inFile:atLine:expected:)' is only available in macOS 10.13 or newer
    testCase.recordFailure(withDescription: "\(name): \(failure.reason)", inFile: failure.file, atLine: failure.line, expected: false)
             ^
/private/tmp/xcodegen-20200717-5913-n8cz13/XcodeGen-2.16.0/.build/checkouts/Spectre/Sources/Spectre/XCTest.swift:35:14: note: add 'if #available' version check
    testCase.recordFailure(withDescription: "\(name): \(failure.reason)", inFile: failure.file, atLine: failure.line, expected: false)
             ^
/private/tmp/xcodegen-20200717-5913-n8cz13/XcodeGen-2.16.0/.build/checkouts/Spectre/Sources/Spectre/XCTest.swift:34:8: note: add @available attribute to enclosing instance method
  func addFailure(_ name: String, failure: FailureType) {
       ^
/private/tmp/xcodegen-20200717-5913-n8cz13/XcodeGen-2.16.0/.build/checkouts/Spectre/Sources/Spectre/XCTest.swift:19:7: note: add @available attribute to enclosing class
class XcodeReporter: ContextReporter {
      ^
make: *** [build] Error 1

Do not report this issue to Homebrew/brew or Homebrew/core!


Error: You are using macOS 11.0.

[Simon Wilson]

Similar problem here with Xcode 12.0 beta (12A6159) on macOS Catalina:

/Users/user/Library/Developer/Xcode/DerivedData/Stencil-master-cvldijxjxhznlgctlhhduodnuvsi/SourcePackages/checkouts/Spectre/Sources/Spectre/XCTest.swift:35:14: 'recordFailure(withDescription:inFile:atLine:expected:)' is only available in macOS 10.13 or newer