in`, we call `runMain` here to have the CommonJS loader begin the
 * execution of the main entry point, even if the ESM loader immediately takes over because the main entry is an ES
 * module or one of the other opt-in conditions (such as the use of `--import`) are met. Users can monkey-patch before
 * the main entry point is loaded by doing so via scripts loaded through `--require`. This monkey-patchability is
 * undesirable and should be removed once the module customization hooks provide equivalent functionality.
 */
require('internal/modules/cjs/loader').Module.runMain(mainEntry);