Testing rx throws error on scheduler init

Question

Unit test terminates if I write var scheduler = TestScheduler(initialClock: 0)

my imports

import XCTest
import RxTest

with error message

failed to demangle superclass of TestScheduler from mangled name '7RxSwift20VirtualTimeSchedulerCy0A4Test0fecD9ConverterVG'

pod versions

pod 'RxBlocking', '~> 5'
pod 'RxTest', '~> 5'

Answer 1

This is a bug of the Cocoapods + XCode 10.2 platform.

Statement from XCode 10.2 RC notes about known issues:

Linking against a static Swift library might create a binary with missing 
type metadata because the object files that define the metadata inside the 
static archive are mistakenly considered unused. (47598583)

This can manifest as a Swift runtime error with a message such as:
“failed to demangle superclass of MyClass from mangled name ‘<mangled name>’”.

Workaround: If you can rebuild the static library, try building it with whole module 
optimization enabled. 
Otherwise, add -all_load to the linker flags in the client binary to 
ensure all object files are linked into it.

This thread and this solution should help you get rid of it.