If interested, you can see their work-in-progress main.rs in the related code revision[0], which includes their Rust code calling down to the C function Py_Init

If interested, you can see their work-in-progress main.rs in the related code revision[0], which includes their Rust code calling down to the C function Py_Initialize() to spin up the now-embedded CPython interpreter that is living "inside" a Rust program: unsafe { Py_Initialize(); PySys_SetArgv(args.len() as c_int, argv.as_ptr()); PyEval_InitThreads(); let _thread_state = PyEval_SaveThread(); } ---- [0] https://phab.mercurial-scm.org/D1581#change-t24aVkGEJ5Xh https://phab.mercurial-scm.org/D1581#change-t24aVkGEJ5Xh