"no such sysroot directory" while building qt project

Question

MacOS Mojave Version 10.14 (18A389).

Today I updated Xcode to version 10.0 (10A255). End when I try to build my Qt project I get an error:

clang: warning: no such sysroot directory: '/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk' [-Wmissing-sysroot]
In file included from ../greed/timediagram.cpp:1:
In file included from ../../../Qt/5.9.1/clang_64/lib/QtGui.framework/Headers/QtGui:3:
In file included from /Users/arsenyspiridonov/Qt/5.9.1/clang_64/lib/QtGui.framework/Headers/QtGuiDepends:3:
In file included from /Users/arsenyspiridonov/Qt/5.9.1/clang_64/lib/QtCore.framework/Headers/QtCore:4:
In file included from ../../../Qt/5.9.1/clang_64/lib/QtCore.framework/Headers/qglobal.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/utility:202:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/cstring:61:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/string.h:61:15: fatal error: 'string.h' file not found
#include_next <string.h>
              ^~~~~~~~~~
1 error generated.
make: *** [timediagram.o] Error 1
16:13:47: Процесс «/usr/bin/make» завершился с кодом 2.
Ошибка при сборке/установке проекта greed (комплект: Desktop Qt 5.9.1 clang 64bit)
Во время выполнения этапа «Сборка»

What's the problem? How to fix it?

Answer 1

add 'QMAKE_MAC_SDK = macosx10.14' to your .pro file, and manually delete .qmake.stash from your build directory (or directories).