OS X: setting @rpath based install names fails on 64bit

Summary

When building and delivering apps for OS X users expect self contained app bundles. This meaning all depending libraries and frameworks not provided by the system should be delivered within the app bundle.

To enable libraries to be location independent install names should be @rpath based (see Mike Ash article).

Qt proposes a post-build step using macdeployqt modifying the install names of Qt frameworks. Setting up such a post build step for bigger projects is inconvenient, macdeployqt is not built with 32bit Qt and this build step should not be necessary if Qt frameworks were built with @rpath based install names.

Steps to reproduce

Build Qt with @rpath based install names:

• download or check out the source code
• add "QMAKE_LFLAGS_SONAME = -Wl,-install_name,@rpath/" to macx make specs:
  qtbase/mkspecs/macx-clang/qmake.conf

  #
  # qmake configuration for Clang on OS X
  #
  
  MAKEFILE_GENERATOR      = UNIX
  CONFIG                 += app_bundle incremental global_init_link_order lib_version_first plugin_no_soname
  QMAKE_INCREMENTAL_STYLE = sublib
  
  include(../common/macx.conf)
  include(../common/gcc-base-mac.conf)
  include(../common/clang.conf)
  include(../common/clang-mac.conf)
  
  QMAKE_MACOSX_DEPLOYMENT_TARGET = 10.6
  
  QMAKE_LFLAGS_SONAME     = -Wl,-install_name,@rpath/
  
  load(qt_config)
  

  qtbase/mkspecs/macx-clang-32/qmake.conf

  #
  # qmake configuration for 32-bit Clang on OS X
  #
   
  MAKEFILE_GENERATOR = UNIX
  CONFIG += app_bundle incremental global_init_link_order lib_version_first plugin_no_soname
  QMAKE_INCREMENTAL_STYLE = sublib
   
  include(../common/mac.conf)
  include(../common/gcc-base-macx.conf)
  include(../common/clang.conf)
  include(../common/clang-mac.conf)
  include(../common/mac-minimum-version.conf)
   
  QMAKE_LFLAGS_SONAME     = -Wl,-install_name,@rpath/
  QMAKE_CFLAGS           += -arch i386
  QMAKE_OBJECTIVE_CFLAGS += -arch i386
  QMAKE_CXXFLAGS         += -arch i386
  QMAKE_LFLAGS           += -arch i386
   
  load(qt_config)
  

• build Qt for 64bit (x86_64):

  $ ../qt5-source/configure -opensource -confirm-license -prefix /opt/qt5/5.2.1beta/x86_64 -xplatform macx-clang -no-c++11 -no-glib -no-dbus -nomake tests -nomake examples
  $ make -j8
  

  and 32bit (i386):

  $ ../qt5-source/configure -opensource -confirm-license -prefix /opt/qt5/5.2.1beta/i386 -xplatform macx-clang-32 -no-c++11 -no-glib -no-dbus -nomake tests -nomake examples
  $ make -j8
  

• use otool to check the install names of the built libraries

Expected behavior

otool should reveal @rpath based install names.

Discovered behavior

• on i386 target (32bit):

  $ otool -L /opt/qt5/5.2.1beta/i386/lib/QtNetwork.framework/QtNetwork
  /opt/qt5/5.2.1beta/i386/lib/QtNetwork.framework/QtNetwork:
          @rpath/QtNetwork.framework/Versions/5/QtNetwork (compatibility version 5.2.0, current version 5.2.1)
          @rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.2.0, current version 5.2.1)
          /System/Library/Frameworks/Security.framework/Versions/A/Security (compatibility version 1.0.0, current version 55179.11.0)
          /usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
          /System/Library/Frameworks/SystemConfiguration.framework/Versions/A/SystemConfiguration (compatibility version 1.0.0, current version 453.19.0)
          /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 744.18.0)
          /System/Library/Frameworks/CoreServices.framework/Versions/A/CoreServices (compatibility version 1.0.0, current version 57.0.0)
          /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 56.0.0)
          /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 169.3.0)
  

• on x86_64 target (64bit):

  $ otool -L /opt/qt5/5.2.1beta/x86_64/lib/QtNetwork.framework/QtNetwork
  /opt/qt5/5.2.1beta/x86_64/lib/QtNetwork.framework/QtNetwork:
          @rpath//opt/qt5/5.2.1beta/x86_64/lib/QtNetwork.framework/Versions/5/QtNetwork (compatibility version 5.2.0, current version 5.2.1)
          @rpath//opt/qt5/5.2.1beta/x86_64/lib/QtCore.framework/Versions/5/QtCore (compatibility version 5.2.0, current version 5.2.1)
          /System/Library/Frameworks/Security.framework/Versions/A/Security (compatibility version 1.0.0, current version 55179.11.0)
          /usr/lib/libz.1.dylib (compatibility version 1.0.0, current version 1.2.5)
          /System/Library/Frameworks/SystemConfiguration.framework/Versions/A/SystemConfiguration (compatibility version 1.0.0, current version 453.19.0)
          /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation (compatibility version 150.0.0, current version 744.18.0)
          /System/Library/Frameworks/CoreServices.framework/Versions/A/CoreServices (compatibility version 1.0.0, current version 57.0.0)
          /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 56.0.0)
          /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 169.3.0)
  

Regression

This behavior was tested and seen with all Qt 5.x versions.

Notes

After quick analyzing the code the problem seems to originate from qmake.