Xcode 10.1: Pods not compiling when running UITest - ios

Question

I am trying to implement UITests in an application I'm working on.
When I am in my UITests.swift file and I try to run the app from a test, Xcode gives the following error for some of the pods I'm using:
Command CompileSwift failed with a nonzero exit code
It gives this error for a bunch of pods that are compiling just fine when running the regular project:
My PodFile looks as follows:
# Uncomment the next line to define a global platform for your project
platform :ios, '9.0'
source 'https://github.com/cocoapods/specs.git'
project 'Project.xcodeproj'
use_frameworks!
# Define all thirdparty pods we need
def thirdparty
pod 'Moya', '~> 11.0'
pod 'Alamofire'
pod 'SwiftyJSON'
pod 'Differ'
.. a bunch of other pods
end
# Pods for Project project
target 'Project' do
thirdparty
end
# Pods for ProjectTests
target 'ProjectUITests' do
thirdparty
pod 'Nimble'
end
I'm having a hard time reasoning why this is happening, as my project normally compiles just fine. Other posts on S.O. regarding this problem report that the problem also occurs when building the project rather than just running for a test
Question How can I make sure that all pods I use in my project, also compile correctly when building from a UITest?

Answer 1

How can I make sure that all pods I use in my project, also compile correctly when building from a UITest?
The only way to know whether something will build or not is to try to build it. So when you change your CocoaPods configuration, even if that's just to update to a newer version of one or more pods, you need to try building each target.
target 'ProjectUITests' do
thirdparty
pod 'Nimble'
end`
According to your Podfile, you've got the pod Nimble being used only in the ProjectUITests target. If that's the only target that fills to build, then it seems likely that that pod is the culprit.
Except for one case (at least as far as you've shown) your Podfile doesn't specify versions for the various pods that it specifies. If you leave out the version for a given pod, your project will use the latest available version. That means that anytime you update your pods you'll pull down the latest version, even if that new version contains breaking changes. It would be safer to specify the version that you know works, or at least to limit the version to minor version and patch updates, like:
pod 'Nimble', '~>7.0'
That will let CocoaPods automatically use the latest version up to but not including 8.0. If the pod developer properly follows the semantic versioning scheme, that should ensure that you don't inadvertently pull in any breaking changes.

Answer 2

The problem is that target :AppModuleTests do do not have an app host and you are using inherit! :search_paths. This means that this target would find the dependencies to load them from the host but in this case there is none.
target TestApp do
pods
target :AppModuleTests
end
This worked for me.