Attachment: Download

Issue Description:

This is currently reproducible with using PromiseKit `after` helper method which causes a crash because of "EXC_BAD_ACCESS (code=EXC_I386_GPFLT)"

• Using latest stable PromiseKit (6.11.0) through SwiftPM

• This started happening in Xcode 11.2 beta 1

• You can reproduce it by calling after(seconds: TimeInterval) anywhere in the code, example:

after(seconds: 2).done {
    print("yay")
}

• The exception is happening in [Guarantee.swift] EXC_BAD_ACCESS (code=EXC_I386_GPFLT)

Attached project can be used to reproduce this. I use Console for reproducing this, but it doesn't happen in a console app:

after(seconds: 2).done {
    print("Yaaay, no crahs!")
}
RunLoop.main.run()