Xcode 4.1 fatal error: stdlib modified since the precompiled header was built

Question

Building an iPhone app, using:

• Xcode 4.1
• Base SDK iOS 4.3
• Apple LLVM Compiler 2.1

I have started getting the following error

Answer 1

Clean ways are not working for me, eventually I solved this issue by reinstall XCode.

Answer 2

Remove the contents for the Simulator by iOS Simulator > Reset Content and Settings... and hit Rest. This will remove any existing pre-compiled instances of the headers and resources. This worked for me

Answer 3

Deleting the DerivedData folder did not work for me when Archiving.

I had to look at Build Settings - Build Locations - Precompiled Header Cache Path and delete that folder.

For me that was:

/var/folders/_w/t0mj70hd1439tqgxff7_mtt00000gn/C/com.apple.Xcode.501/SharedPrecompiledHeaders

Answer 4

I was able to fix it in a much easier way, by simply choosing Product > Clean, then Product > Build from the Xcode menubar.

Answer 5

I thought I would add a separate answer rather than a comment to Cryptognome's answer, because it is in fact a different solution when the issue comes from running xcodebuild. Like Cryptognome, I had the error come up with the command-line tool xcodebuild. As an alternative to manually going into the /var subfolders, I found that I could set my own cache for the shared PCH, which you can do by setting the environment variable SHARED_PRECOMPS_DIR, e.g as follows

xcodebuild -target Foo -configuration Release SHARED_PRECOMPS_DIR=/tmp/foo/SharedPCH

This way, I never get the error in automatic builds.

Note in the above command, I would also typically set the OBJROOT and SYMROOT env var to build also in /tmp. At the end, I clean things up.

Answer 6

I tried above all but no use. Finally I deleted Xcode and re installed again. Now it is working fine..

Xcode->delete->install again

It might help some one...