Reopening this topic because I am still encountering this issue.
Doesn’t look like a resolution was reached in the previous locked thread Chapter 3 RxRelay
I have checked the “Build Active Scheme” box but still see the error.
It’s preventing me from performing any of the work using Relays.
I’m currently running Xcode 12.5.1 and see this error after running ./bootstrap.sh and opening the workspace file.