Build fails with: error: static_assert failed due to requirement 'bool(QAtomicOpsSupport<sizeof(unsigned long long)>::IsSupported)' "template parameter is an integral of a size not supported on this platform"

clang++ -c -pipe -g -std=c++1z -fvisibility=hidden -fvisibility-inlines-hidden -Wall -W -D_REENTRANT -fPIC -DQT_NO_USING_NAMESPACE -DQT_NO_FOREACH -DELF_INTERPRETER=\"/lib64/ld-linux-x86-64.so.2\" -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_BUILD_CORE_LIB -DQT_BUILDING_QT -DQT_NO_CAST_TO_ASCII -DQT_ASCII_CAST_WARNINGS -DQT_MOC_COMPAT -DQT_USE_QSTRINGBUILDER -DQT_DEPRECATED_WARNINGS -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -Wall -Wextra -Werror -Woverloaded-virtual -Wshadow -Wundef -Wfloat-equal -Wnon-virtual-dtor -Wpointer-arith -Wformat-security -Wno-long-long -Wno-variadic-macros -pedantic-errors -Wchar-subscripts -Wold-style-cast -Wcast-align -I/home/johan/dev/qt/dev/qtbase/src/corelib -I. -Iglobal -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/harfbuzz/src -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/md5 -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/md4 -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/sha3 -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/forkfd -I/home/johan/dev/qt/dev/qtbase/src/3rdparty/tinycbor/src -I../../include -I../../include/QtCore -I../../include/QtCore/5.13.0 -I../../include/QtCore/5.13.0/QtCore -I.moc -I.tracegen -isystem /usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/home/johan/dev/qt/dev/qtbase/mkspecs/linux-clang -DQT_NO_CAST_TO_ASCII=1 -DQT_NO_CAST_FROM_ASCII=1 -UQT_RESTRICTED_CAST_FROM_ASCII -DQT_STRICT_ITERATORS -DQT_NO_URL_CAST_FROM_STRING=1 -DQT_NO_CAST_FROM_BYTEARRAY=1 -DQT_NO_KEYWORDS=1 -DQT_USE_QSTRINGBUILDER -DQT_USE_FAST_OPERATOR_PLUS -Dsignals=int -Dslots=int -Demit=public: -Dforeach=public: -Dforever=public: -xc++ /home/johan/dev/qt/dev/qtbase/src/corelib/tools/qscopedvaluerollback.h -o .obj/header_qscopedvaluerollback.o
In file included from /home/johan/dev/qt/dev/qtbase/src/corelib/thread/qsemaphore.h:43:
In file included from ../../include/QtCore/qglobal.h:1:
In file included from ../../include/QtCore/../../../../../dev/qtbase/src/corelib/global/qglobal.h:1218:
In file included from ../../include/QtCore/qatomic.h:1:
In file included from ../../include/QtCore/../../../../../dev/qtbase/src/corelib/thread/qatomic.h:46:
In file included from ../../include/QtCore/qbasicatomic.h:1:
../../include/QtCore/../../../../../dev/qtbase/src/corelib/thread/qbasicatomic.h:97:5: error: static_assert failed due to requirement 'bool(QAtomicOpsSupport<sizeof(unsigned long long)>::IsSupported)' "template parameter is an integral of a size not supported on this platform"
    Q_STATIC_ASSERT_X(QAtomicOpsSupport<sizeof(T)>::IsSupported, "template parameter is an integral of a size not supported on this platform");
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../include/QtCore/../../../../../dev/qtbase/src/corelib/global/qglobal.h:121:49: note: expanded from macro 'Q_STATIC_ASSERT_X'
#  define Q_STATIC_ASSERT_X(Condition, Message) static_assert(bool(Condition), Message)
                                                ^             ~~~~~~~~~~~~~~~
/home/johan/dev/qt/dev/qtbase/src/corelib/thread/qsemaphore.h:70:39: note: in instantiation of template class 'QBasicAtomicInteger<unsigned long long>' requested here
        QBasicAtomicInteger<quintptr> u;        // ### Qt6: make 64-bit
                                      ^
1 error generated.
make[3]: *** [Makefile:13293: .obj/header_qsemaphore.o] Error 1
make[3]: *** Waiting for unfinished jobs....
make[3]: Leaving directory '/home/johan/dev/qt/build/dev-no-server/qtbase/src/corelib'
make[2]: *** [Makefile:173: sub-corelib-make_first] Error 2
make[2]: Leaving directory '/home/johan/dev/qt/build/dev-no-server/qtbase/src'
make[1]: *** [Makefile:51: sub-src-make_first] Error 2
make[1]: Leaving directory '/home/johan/dev/qt/build/dev-no-server/qtbase'
make: *** [Makefile:88: module-qtbase] Error 2

-commercial
-confirm-license
-developer-build
-nomake
examples
-nomake
tests
-no-pch
-no-warnings-are-errors
-no-use-gold-linker
-platform
linux-clang
-no-feature-vnc
-no-linuxfb

looking for library libatomic
Trying source 0 (type inline) of library libatomic ...                                                                 atomic not found in [] and global paths.                                                                               cstdint not found in [] and global paths.
  => source produced no result.
Trying source 1 (type inline) of library libatomic ...
atomic not found in [] and global paths.
cstdint not found in [] and global paths.
  => source produced no result.
test config.qtbase_corelib.libraries.libatomic FAILED

Global lib dirs: [] [/usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1 /usr/lib /lib /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.1]
Global inc dirs: [] [/usr/include/c++/6.1.1 /usr/include/c++/6.1.1/x86_64-pc-linux-gnu /usr/include/c++/6.1.1/backward /usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/include /usr/local/include /usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/include-fixed /usr/include /usr/include/c++/6.3.1 /usr/include/c++/6.3.1/x86_64-pc-linux-gnu /usr/include/c++/6.3.1/backward /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.1/include /usr/local/include /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.1/include-fixed /usr/include]

error("QMAKE_DEFAULT_INCDIRS $$QMAKE_DEFAULT_INCDIRS")

Creating qmake...
...........................................................................................Done.
Project ERROR: QMAKE_DEFAULT_INCDIRS /usr/include/c++/6.1.1 /usr/include/c++/6.1.1/x86_64-pc-linux-gnu /usr/include/c++/6.1.1/backward /usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/include /usr/local/include /usr/lib/gcc/x86_64-pc-linux-gnu/6.1.1/include-fixed /usr/include