Xcode 9 - failed to emit precompiled header

Question

I have a project in Objective-C as well as in swift by taking MyProjectName-Bridging-Header.h and i also configured the Objective-C Bridging Header. Also i have added 'MyprojectName-Swift.h' in .pch file.

This works fine on xcode 8.2 but when i build my project from xcode 9 i am getting the below error.

failed to emit precompiled header '/Library/Developer/Xcode/DerivedData/MyprojectName-lajanjvhqjnfjksdsndsfkads/Build/Intermediates.noindex/PrecompiledHeaders/MyprojectName-Bridging-Header-swift_44AHJm3Z96qu-clang_2BIMGQVXGEZ09.pch' for bridging header '/Documents/MyProjectLocaiton/FoneApp-Bridging-Header.h'

Please help me out from this. Thanks!

Force quit the Xcode, delete the derived data, open Xcode clean your build and then run project — Gourav Joshi, Sep 19 '17 at 06:15
@GouravJoshi Thanks for the responce, I have already done all these tasks. But still have the same issue — Shubham, Sep 19 '17 at 06:19
I have the same problem, but I have not found any solution yet. — Tomasz Nazarenko, Sep 20 '17 at 18:33
@Maddy I got the solution of this issue, Hope this works for you too. — Shubham, Sep 21 '17 at 15:38

score 28 · Answer 1 · answered Mar 07 '18 at 07:24

28

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!

answered Mar 07 '18 at 07:24

nikdange_me

2,949
2
16
24

Ivan Besarab · Answer 2 · 2017-10-02T10:11:23.147

24

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.

edited Oct 02 '17 at 10:11

answered Oct 02 '17 at 09:57

Ivan Besarab

990
7
12

1

Thanks! I had this issue while merging branches, my podfile was set to platform :ios, '10.3' while my xcode minimum deployment target was still at 10.0, you need to change it to 10.3 in xcode THEN run pod install – xGoPox Feb 07 '19 at 12:19

score 15 · Answer 3 · answered May 04 '18 at 00:36

15

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

answered May 04 '18 at 00:36

Elijah

8,381
2
55
49

1

I've put it on .h files, it works fine, that's not the problem – Gustavo Parrado May 08 '18 at 19:09
4

@Harris this was the workaround for me. Thank you. – Daniel Dramond Jun 27 '18 at 08:49
2

You may also need to forward-declare classes and protocols in the .h file: https://developer.apple.com/documentation/swift/imported_c_and_objective-c_apis/importing_swift_into_objective-c – musical_coder Aug 02 '19 at 01:09

Shubham · Accepted Answer · 2017-09-21T15:40:37.343

12

Finally i got the solution of this issue. In my project the Prefix Header path is not clearly defined. Earlier the path was

$(SRCROOT)/MyPrefixHeaderFile.pch

MyPrefixHeaderFile.pch is in another folder inside the project folder, So i update the Prefix Header path to

$(SRCROOT)/FolderName/MyPrefixHeaderFile.pch

edited Sep 21 '17 at 15:40

answered Sep 21 '17 at 15:35

Shubham

1,230
2
12
26

7

How did you do this? – Wide Angle Technology Oct 08 '19 at 08:06

score 10 · Answer 5 · edited Apr 11 '22 at 15:47

10

Maybe you created a new target, but forgot to add this to your Podfile:

target 'Pistachio-rrzcpjs' do

end

edited Apr 11 '22 at 15:47

ZGski

2,398
1
21
34

answered Jan 08 '18 at 09:07

Li Yakun

117
1
2

The only answer worked with me..thanks man :+1: – Elsammak Aug 09 '18 at 05:55
1

The answer really helped me when I tried to run unit tests. The only thing I needed was to add something like: "target :AppTests do #some pods end" in podfile – Iulian Nikolaiev Sep 22 '21 at 12:02

Okan · Answer 6 · 2019-02-25T13:03:46.887

7

You can try this solution. I have solved the same problem by this way.

Product > Scheme > Edit Scheme > Select "Build" on Left Menu > Find implicit dependencies

Under the build tab, check 'Find implicit dependencies':

Find implicit dependencies

Then make a clean and build again.

edited Feb 25 '19 at 13:03

answered Nov 02 '17 at 09:17

Okan

410
4
10

perfect, i had disabled it to inprove build time , and then i forgot, thanks buddy – Harshad Madaye Mar 12 '18 at 08:00

score 7 · Answer 7 · answered Mar 15 '18 at 10:03

7

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

answered Mar 15 '18 at 10:03

Anand

216
3
10

I was -project and it does not work with *.xworkspace. -workspace solved :) – Ronaldo Albertini Nov 22 '19 at 19:22

score 4 · Answer 8 · answered Nov 07 '17 at 09:04

4

in my point of view I solved simply switch the order of import statements and build works fine.

answered Nov 07 '17 at 09:04

Alessio Campanelli

970
11
19

Really it matters! – iOS Sep 10 '18 at 08:31

Benzi Heler · Answer 9 · 2017-09-24T11:48:40.263

3

In my case I had the same compiler error with additional errors like "Unknown type" in one of my project files, So I just added this to the problematic file, and it solved it instantly.

#import <UIKit/UIKit.h>

edited Sep 24 '17 at 11:48

answered Sep 24 '17 at 11:42

Benzi Heler

1,138
1
10
18

score 3 · Answer 10 · answered Mar 16 '18 at 13:13

3

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

answered Mar 16 '18 at 13:13

Marc-Alexandre Bérubé

2,161
16
26

This happen to me too, How do you fix this things? – Jefferson Setiawan Jun 12 '18 at 07:43
1

Sorry for the delay, you must make sure your header files imported in the bridging header contains all of their dependencies (even those who were implied from the Prefix header) – Marc-Alexandre Bérubé Aug 15 '18 at 12:23

score 2 · Answer 11 · answered Mar 23 '18 at 17:40

2

@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

answered Mar 23 '18 at 17:40

clopex

459
6
11

Quite unlike the other suggestions here, this worked for me – Raphael Jun 09 '22 at 19:08

score 0 · Answer 12 · answered Feb 20 '18 at 21:00

0

Also if you have multiple targets, be aware to include your #imports in every file.

answered Feb 20 '18 at 21:00

Gabriel Oliva

143
1
11

Xcode 9 - failed to emit precompiled header

12 Answers12

Linked