Tuesday, April 10, 2012

App crashes with 4.2 iPhone simulator "set start-with-shell off"

I'm writing application which perfectly works on 4.0/4.1 iPhone simulator, but not 4.2.

I'm getting such warning:

Detected an attempt to call a symbol in system libraries that is not present on the iPhone: fcntl$UNIX2003 called from function get_socket_nonblocking in image TestApp. If you are encountering this problem running a simulator binary within gdb, make sure you 'set start-with-shell off' first.

How to set 'set start-with-shell off' on Xcode? I'm tried to add this line to .gdbinit but without luck.

With 4.0/4.1 SDK iPhone Simulator prints warnings about attempt to call symbol that is not present on the iPhone in debug window, but app don't crashes. Using using 4.2 app crashes. How to prevent 4.2 crashes ?


Source: Tips4all


  1. before this cleanAll build then

    In xcode go to Project > set active executable > appname - Iphone 4.0 simulator

    then open simulator then go to Hardware > version > 4.0.2

    then double click urapptarget and in build tab change "ios deployment target = 4.0"

    now run in simulator it will work

  2. File a bug via http://bugreporter.apple.com/

    The debugger within Xcode will read ~/.gdbinit just like gdb at the command line. Try adding that line to ~/.gdbinit.

  3. I had a similar problem with a version of libCURL that was built for an earlier OS. The solution was to rebuild the library under iOS 4.2 to eliminate the $UNIX2003 symbol decorations. (I wrote up the full details at http://www.creativealgorithms.com/blog/content/building-libcurl-ios-42.)

  4. I was also unsuccessful adding the line to ~/.gdbinit. At the risk of stating the obvious: if you set the simulator version to 4.1 within XCode, you'll avoid the issue. This is what I do now - which is fine as long as I don't need to test an API available only on 4.2 - which we do not (we still target iOS 3.0).

  5. I encountered a similar error:

    Detected an attempt to call a symbol in system libraries that is not present on the iPhone:
    pthread_rwlock_init$UNIX2003 called from function ...

    I was able to fix by unchecking the 'Strip linked Product' Deployment Build Setting of the Project, ie STRIP_INSTALLED_PRODUCT = NO

    Don't forget to do a full clean before rebuilding.

    You probably only want to do this for the simulator. Filling a bug report is still a good idea.

  6. If you are using native libraries, you should recompile them using iOS4 (only the i386 versions, as it works on the device).

  7. The $2003 suffix is generated by the compiler under some circumstances which you can find fully documented in the manual entry for compat

    man compat

    I wrestled with this for some time before finally fixing it by setting


    Any version prior to 10.4 will do the job.

    Hope this helps.