Qt 5.7 WebEngine on OSX 10.9 with XCode 5.1.1

To succesfully build Qt 5.7 WebEngine on OSX 10.9 with XCode 5.1.1, the following items are required:

XCode 5.1.1 for the toolchain
XCode 6.3 for the OSX 10.10.3 SDK

XCode 6.2 which is the last supported version to run on OSX 10.9 does not contain the latest 10.10 SDK (which is 10.10.3, which introduced Force Touch APIs in a patch release, used by Chromium starting with version 49....).

Then do the following steps:

Extract XCode 5.1.1 into /Application/XCode511/Xcode.app
Extract XCode 6.3 into /Application/XCode63/Xcode.app
Run the following code:

cp -r /Application/XCode63/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk /Applications/XCode511/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs
sudo xcode-select --switch /Applications/XCode511/Xcode.app/Contents/Developer

Build Qt / Qt WebEngine
Restore the usual XCode after you're done, with:

sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer

OSX 10.11 (El Capitan) with XCode 5.1.1

All the information below does not guarantee the whole process will succeed for you, as it did for me.

The same procedure, with possible slight adjustments in src/core/config/mac_osx.pri, can be used to build a project on OSX 10.11 El Capitan with XCode 5.1.1 (XCode itself won't open, but the build tools seem to work correctly (at least Qt WebEngine was successfully built with it, and ran normally)).

One small issue that might happen on El Capitan is that the ld linker from XCode 5.1.1 might refuse to work, specifically hang and eat CPU. To fix that, you can use the following procedure:

Run sudo opensnoop -n ld in a terminal
Run ld -v in another terminal
The first terminal will output something like:

  UID    PID COMM          FD PATH
  501  82018 ld             3 /usr/lib/libxcselect.dylib
  501  82018 ld             3 /dev/dtracehelper
  501  82018 ld             3 /Applications/XCode511/Xcode.app/Contents/Developer/usr/lib/libxcrun.dylib
  501  82018 ld             3 /var/folders/_x/l798cjd52ql19nfxydb17_c80000gn/T/xcrun_db
  501  82018 ld             3 /dev/dtracehelper
  501  82018 ld             3 /Applications/XCode51/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/libLTO.dylib

Kill both of the processes with Ctrl-C
Backup, or remove the /var/folders/_x/l798cjd52ql19nfxydb17_c80000gn/T/xcrun_db file
Running ld -v should now properly return:

$ ld -v
@(#)PROGRAM:ld  PROJECT:ld64-236.4
configured to support archs: armv6 armv7 armv7s arm64 i386 x86_64 armv6m armv7m armv7em
LTO support using: LLVM version 3.4svn

Note that you will need to disable DTrace SIP protection (rootless mode) on El Capitan, so that opensnoop works properly.

mac_osx.pri adjustments

For development purposes, if you don't want to rebuild the whole of Qt with XCode 5.1.1, you can rebuild only the Chromium part of Qt WebEngine by modifying the path to the compiler and SDK in /path/to/qt/source/qtwebengine/src/core/config/mac_osx.pri.

Specifically override:

QMAKE_MAC_SDK_PATH -> "/Applications/XCode511/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk",
QMAKE_CLANG_PATH -> "/Applications/XCode511/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++"
QMAKE_MAC_SDK_VERSION -> macosx10.10
mac_sdk_min -> \"10.10\"

alcroito/qt57_webengine_xcode_511_osx_sdk_10_10_on_el_capitan.md

Qt 5.7 WebEngine on OSX 10.9 with XCode 5.1.1

OSX 10.11 (El Capitan) with XCode 5.1.1

mac_osx.pri adjustments