"Redefinition of module ..." when building for simulator

Question

I have an iOS xcode project that builds fine when I have Generic iOS Device selected as my destination. However, when I select any of the simulator options I the build fails with many Redefinition of module 'abcde', one error for every module defined in iOS 11.4/usr/include/module.modulemap.

The duplicate definitions are coming from Simulator - iOS 11.4/usr/include/module.modulemap. I've combed through my workspace/project settings and found no reference to the simulator. All the deployment targets are iOS 11.4.

It appears that when I build for the simulator it is including both the platform and simulator modules. How can I specify one or the other?

This problem popped up out of the blue about a day after adding cocoapods and swift code but I don't know if it is related. (The sdk/deployment targets for the pods are also iOS 11.4 and swift version is 4 (except for Socket.IO which is using 3)).

My pods project is using the generated modulemap (I haven't edited it at all):

framework module Pods_MyProjectName {
  umbrella header "Pods-MyProjectName-umbrella.h"

  export *
  module * { export * }
}

I've googled this problem over and over and haven't been able to find any solution for it. I've tried cleaning and rebuilding, deleting the contents of the Library/Developer/Xcode/DerivedData folder, deleting the pod's modulemap file, commenting out each line of the pod's modulemap file, removing all the code written since the problem began... I have the feeling that I'm looking in all the wrong places.

Eames

I came into work this morning and tried building for the simulator again to get the errors to show so I could go digging again. ... The problem has evaporated overnight without any visible trace of why. Gonna chalk this up to some configuration issue that was solved by a system reboot and move on. – Eames

Answer 1

I had the same issue with other pods. I assume the issue has to do with recursive dependecnies that are also imported explicitly. I tried all the same things as you did, although the only thing that helped me was to close xcode, run

pod deintegrate
pod install

and rebuild.

Incur

Hello, this did not work on me, do you have an other suggestion ? – Klement

check if the other pod in your project is using CommonCrypto inside itself. e.g. TPInAppReceipt – Karimakarin

Answer 2

I have just ran into this with a CapacitorJS app. I have tried many of the solutions presented in the various forums and answers on here. What finally fixed it for me was I had the following environment variable set

CPATH="/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include"

For me this was being exported in my .zshrc file so dependant on your shell I'd check for occurances of this.

Adhern

Answer 3

If you have a module that needs a modular header, you need to add to the following sentence to your podfile:

pod 'GoogleUtilities', :modular_headers => true

Voyeur

Answer 4

Exact reasons for this error are ::

• If you have updated react native version.
• If you are using firebase in your project.

Note :: In earlier version of react native there we were using Flipper , but in newer versions of react native we are going to use Kotlin . So above error is of firebase. You need to change some setting related to firebase and deprecated Flipper. I recommend to follow these steps from official website of firebase setup. https://rnfirebase.io/#altering-cocoapods-to-use-frameworks

• Step1 :: Add these lines right above the use_react_native in pod file . Path is ./ios/Podfile

use_frameworks! :linkage => :static

$RNFirebaseAsStaticFramework = true

-Step2 :: Remove all code from podfile related to flipper.

-Step3 :: Hit this command pod install --repo-update

-Step4 :: Clean your xcode build using keys command+shift+k

-Step5 :: Run your project.

Hernia