Python debugger doesn't launch

I am trying to debug an extremely simple python file:

print('hi')
print('hello') # debug line set here

with an extremely simple debug launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Current File",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "integratedTerminal",
            "justMyCode": true
        }
    ]
}

When I press F5, nothing happens. When I go to the Run and Debug panel, and click on the debug play button, nothing happens.
And I really mean absolutely nothing happens: no popups, no errors, no messages, no debug terminal, no logs (that I can find), nada.