Run JS code from within a C++ addon that contains "require" - node.js

Question

I would like to run JS code from within the C++ node.js addon.
What i tried is this:
// addon C++ snipplet (just added to the simple example addon code
static NAN_METHOD(RunScript) {
MyObject* obj = ObjectWrap::Unwrap<MyObject>(info.Holder());
v8::Local<v8::String> s = info[0]->ToString();
v8::Local<UnboundScript> script = Nan::New<UnboundScript>(s).ToLocalChecked();
MaybeLocal<v8::Value> result = Nan::RunScript(script);
info.GetReturnValue().Set(result.ToLocalChecked());
}
When i load this addon from JS, I can run simple scripts:
// JS code
var OB = require('./build/Debug/objectwraphandle.node')
var obj1 = new OB.MyObject(42)
var returns = obj1.runScript("2+3");
console.log("returned: " + returns);
// ==> writes out 5, as expected
But when i write this:
// JS code
var OB = require('./build/Debug/objectwraphandle.node')
var obj1 = new OB.MyObject(42)
var returns = obj1.runScript("var express = require('express');")
I get:
FATAL ERROR: v8::ToLocalChecked Empty MaybeLocal.
1: node::Abort() [node]
2: 0x565373d379b1 [node]
3: v8::Utils::ReportApiFailure(char const*, char const*) [node]
4: v8::MaybeLocal<v8::UnboundScript>::ToLocalChecked()
[/home...objectwraphandle.node]
5: MyObject::RunScript(Nan::FunctionCallbackInfo<v8::Value> const&)
[/home/.../objectwraphandle.node]
6: 0x7f493bc79dc6 [/home/.../objectwraphandle.node]
7: v8::internal::FunctionCallbackArguments::Call(void (*)
(v8::FunctionCallbackInfo<v8::Value> const&)) [node]
What am I doing wrong here?
Why may my JS snipplets that I want to run not contain "require"?
Calls to "console.log" work fine. (If there are other limitations, I did not see them so far)