RxCocoa build fails on XCode 9 Beta 3

[pawartur]

Short description of the issue:

I can't compile my workspace with RxCocoa 3.6.0 added as a pod with workspace's swift version set to 3.0.

Expected outcome:

I'd like to be able to compile my workspace...

What actually happens:

Undefined symbols for architecture arm64:
  "__T07RxCocoa0A28PickerViewSequenceDataSource33_B01E1C82A05E47F6D9AB6B2211DAC570LLCyxGAA0acdfG4TypeAAs0E0RzlWa", referenced from:
      __T07RxSwift8ReactiveV0A5CocoaSo12UIPickerViewCRbzlE10itemTitlesAA10Disposable_pSSSgSi_7ElementQyd__tccqd_0_s8SequenceRd__1EQyd_0_Rsd__AA14ObservableTypeRd_0_r0_lFAaH_pAISi_AKtccfU_ in UIPickerView+Rx.o
      __T07RxSwift8ReactiveV0A5CocoaSo12UIPickerViewCRbzlE20itemAttributedTitlesAA10Disposable_pSo18NSAttributedStringCSgSi_7ElementQyd__tccqd_0_s8SequenceRd__1EQyd_0_Rsd__AA14ObservableTypeRd_0_r0_lFAaH_pAKSi_AMtccfU_ in UIPickerView+Rx.o
      __T07RxSwift8ReactiveV0A5CocoaSo12UIPickerViewCRbzlE5itemsAA10Disposable_pSo6UIViewCSi_7ElementQyd__AJSgtccqd_0_s8SequenceRd__1EQyd_0_Rsd__AA14ObservableTypeRd_0_r0_lFAaH_pAJSi_AlMtccfU_ in UIPickerView+Rx.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Self contained code example that reproduces the issue:
No code needed.

RxSwift/RxCocoa/RxBlocking/RxTest version/commit

The latest commit with pod version == 3.6.0 as of the time of writing this

Platform/Environment

• iOS
• macOS
• tvOS
• watchOS
• playgrounds

How easy is to reproduce? (chances of successful reproduce after running the self contained code)

• easy, 100% repro
• sometimes, 10%-100%
• hard, 2% - 10%
• extremely hard, %0 - 2%

Xcode version:

  Xcode 9 beta 3

Installation method:

• CocoaPods
• Carthage
• Git submodules

I have multiple versions of Xcode installed:
(so we can know if this is a potential cause of your issue)

• yes (11 beta 3 and 8.3.3)
• no

Level of RxSwift knowledge:
(this is so we can understand your level of knowledge
and formulate the response in an appropriate manner)

• just starting
• I have a small code base
• I have a significant code base

[freak4pc]

I believe you're referring to Xcode 9.

Please follow issue #1341