Xcode 9 - failed to emit precompiled header [duplicate]

Answer 1

When you are getting this error in terminal upon running the xcodebuild command, do make sure you pass -workspace YourWorkspace.xcworkspace

Answer 2

I found out that I accidentally opened the ProjectName.xcodeproj file rather than the ProjectName.xcworkspace file.

Open the xcworkspace file, project will start working again!

Answer 3

Also make sure your import of "ProductModuleName-Swift.h" is in your .m file, and not your .h file.

Answer 4

Read this if you using cocoapods in project. I just update deployment target to iOS 10 or 11 in my case after updating pods and xcode make first build success. So problem was inside podfile where I had line

platform :ios, '11.0'

and my deployment target in project was 9.0 after I change my podfile to platform to

platform :ios, '9.0'

project was fixed.

Answer 5

@Li Yakun This is the solution if you have more then one target in project, every new target in podfile must have:

target 'NEWTARGET' do
    # Comment the next line if you're not using Swift and don't want to use dynamic frameworks
    use_frameworks!

    # Pods for MAINTARGET
    shared_pods
end

Answer 6

Adding my very own situation to the loop.

In my bridging header file, le'Ts say I added an import

#import "File.h"

Inside the File.h header file, there was a type referenced from an import that was inside the Prefix.pch, had to add the missing #import in my File.h