这是原因是你当前的系统不是macosx10.8,要在Qt文件中修改。
The problem is that the online installer for Qt currently supports OSX 10.8 (Mountain Lion) by default, and I'm guessing you are on 10.9 (Mavericks) or greater.
There is a workaround:
!host_build:QMAKE_MAC_SDK = macosx10.8
to: !host_build:QMAKE_MAC_SDK = macosx10.9
if you are on OS X 10.9 (Mavericks), or!host_build:QMAKE_MAC_SDK = macosx
if you are on OS X 10.10 (Yosemite)我的是10.12,将 5.3/clang_64/mkspecs/qdevice.pri文件下的!host_build:QMAKE_MAC_SDK = macosx10.8 改为 !host_build:QMAKE_MAC_SDK = macosx10.12 就OK啦。