Executing

const neverLinked = new vm.Module('import "nonexistent";');
// Note: `await` intentionally omitted as the returned promise will never resolve.
neverLinked.link(() => new Promise(() => {}));

const main = new vm.Module('import "neverLinked";');
await main.link(() => neverLinked);
main.instantiate();

with --experimental-vm-modules throws

internal/vm/Module.js:170
    wrap.instantiate();
         ^
Error: linking error, dependency promises must be resolved on instantiate
    at Module.instantiate (internal/vm/Module.js:170:10)

which does not have the error code that is present on all other errors thrown by instantiate(). In comparison,

new vm.Module('').instantiate();

throws an error with a proper error code:

Error [ERR_VM_MODULE_NOT_LINKED]: Module must be linked before it can be instantiated

The thrown error comes from

which due to restrictions on how V8's C++ API operates makes it inconvenient to add the error code. The way to fix this would be to wrap a try-catch block around

to throw a proper errors.Error. The error message can be hard-coded as Linked dependencies must all be linked before instantiation, since this should be the only possible error thrown from this line.

See also #18106.