Debugger on macOS treats a single argument with spaces inside double quotes as multiple arguments

In my run settings I have a command line argument containing spaces, "foo bar", enclosed in double quotes. When I try to run in QtCreator's debugger this always gets split into two arguments, i.e. the double quotes are ignored. This only happens in the debugger. When running outside the debugger, "foo bar" gets treated correctly as just one argument.

You can see this even with a trivial test program that just prints out argc and argv:

#include <iostream>
using namespace std;
int main(int argc, char** argv) {
  cout << "argc = " << argc << endl;
  for (int i = 0; i < argc; i++)
    cout << "argc[" << i << "] = " << argv[i] << endl;
  return 0;
}

For example, if I run myprog "foo bar" in the debugger, I can see that

  argc = 3
  argv[0] = myprog
  argv[1] = foo
  argv[2] = bar

so it looks like the double quotes have been stripped before argument parsing happens. However when running with the exact same arguments outside the debugger I get the correct result:

  argc = 2
  argv[0] = myprog
  argv[1] = "foo bar"

This is a major problem because it means you can't pass a filename containing spaces into your program when debugging.