Function import_builtin

crates/vm/src/import.rs:92–123

(vm: &VirtualMachine, module_name: &str)

}

pub fn import_builtin(vm: &VirtualMachine, module_name: &str) -> PyResult {
    let sys_modules = vm.sys_module.get_attr("modules", vm)?;

    // Check if already in sys.modules (handles recursive imports)
    if let Ok(module) = sys_modules.get_item(module_name, vm) {
        return Ok(module);
    }

    // Try multi-phase init first (preferred for modules that import other modules)
    if let Some(&def) = vm.state.module_defs.get(module_name) {
        // Phase 1: Create and initialize module
        let module = def.create_module(vm)?;

        // Add to sys.modules BEFORE exec (critical for circular import handling)
        sys_modules.set_item(module_name, module.clone().into(), vm)?;

        // Phase 2: Call exec slot (can safely import other modules now)
        // If exec fails, remove the partially-initialized module from sys.modules
        if let Err(e) = def.exec_module(vm, &module) {
            let _ = sys_modules.del_item(module_name, vm);
            return Err(e);
        }

        return Ok(module.into());
    }

    // Module not found in module_defs
    Err(vm.new_import_error(
        format!("Cannot import builtin module {module_name}"),
        vm.ctx.new_utf8_str(module_name),
    ))
}

#[cfg(feature = "rustpython-compiler")]
pub fn import_file(