Amplitude-iOS is a dependency of ExpoKit (this is shown in ExpoKit.podspec). It should have been installed automatically when you ran pod install in your detached project. Does your Podfile.lock show that cocoapods has some version of Amplitude present?
Hmm, I’m not sure I have enough information to say. Something is trying to link against Amplitude and doesn’t know where to find Amplitude. I haven’t seen this happen in an ExpoKit project before but it might be particular to the library you added, or something about the way your search paths are configured. Here’s some general ideas (without knowing much about your situation):
Figure out which target is looking for Amplitude and failing
See whether it actually needs Amplitude. If not, maybe there’s an erroneous setting telling it to link against Amplitude.
If it does, make sure the Framework Search Paths make sense for that target.
OK, some headway. After removing derived files, cleaning and rebuilding, I started getting a different error related to duplicate symbols.
I then set up an empty test build and started adding and building packages 1-by-1. It seems to be getting stuck on react-native-static-server (opened issue here: 46 Duplicate symbols for architecture x86_64 · Issue #4 · futurepress/react-native-static-server · GitHub), producing the same duplicate symbole error. I’ll keep you posted.
I was experiencing the same issue until I decided to reread the configuration instructions and realized I was opening the xcodeproj instead of the xcworkspace file.
In the end this problem was related to Header Search paths, which are kind of a pain to deal with. Different libraries that you link to expo will look for the headers in different locations, so you for each linked package, you have to see where it’s base xcode file is, and add a relative header search path that points to the headers correctly. See here: https://docs.expo.io/versions/latest/guides/expokit.html
I’ve also had this issue, but it was because I’ve disabled Find Implicit Dependencies in Xcode > Product > Scheme > Edit Scheme, so it might be helpful if anyone have done the same and forgot about it.