I'm not able to clazy analyze this example:

#include <type_traits>

int main(int argc, char **argv)
{
  return 0;
}

The system has a standard XCode 12.1 Setup with command line tools installed.

/Users/njeiseck/xxx/dummy.cpp:2:10: fatal error: 'type_traits' file not found
#include <type_traits>
         ^~~~~~~~~~~~~
1 error generated.

Workaround (kind of):

'/usr/local/Qt/Qt Creator 4.14.0-beta2.app/Contents/Resources/libexec/clang/bin/clazy-standalone' dummy.cpp -- -I /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1

But adding this include path is probably not a correct solution and I can't find any UI to add custom arguments for running this from within Qt Creator anyway.

Same problem is with clazy compiled from https://invent.kde.org/sdk/clazy.git so I'm unsure if this is really a problem with QtCreator or rather with my setup (which is nothing special).