The snapshot currently only supports loding a single entrypoint during the

snapshot building process, which can load built-in modules, but not additional user-land modules.

Users can bundle their applications into a single script with their bundler

of choice before building a snapshot.

As it's complicated to ensure the serializablility of all built-in modules,

which are also growing over time, only a subset of the built-in modules are

well tested to be serializable during the snapshot building process.

The Node.js core test suite checks that a few fairly complex applications

can be snapshotted. The list of built-in modules being

[captured by the built-in snapshot of Node.js][] is considered supported.

When the snapshot builder encounters a built-in module that cannot be

serialized, it may crash the snapshot building process. In that case a typical

workaround would be to delay loading that module until

runtime, using either [`v8.startupSnapshot.setDeserializeMainFunction()`][] or

[`v8.startupSnapshot.addDeserializeCallback()`][]. If serialization for

an additional module during the snapshot building process is needed,

please file a request in the [Node.js issue tracker][] and link to it in the

[tracking issue for user-land snapshots][].

[`v8.startupSnapshot.addDeserializeCallback()`]: v8.md#v8startupsnapshotadddeserializecallbackcallback-data

[`v8.startupSnapshot.setDeserializeMainFunction()`]: v8.md#v8startupsnapshotsetdeserializemainfunctioncallback-data

[captured by the built-in snapshot of Node.js]: https://github.com/nodejs/node/blob/b19525a33cc84033af4addd0f80acd4dc33ce0cf/test/parallel/test-bootstrap-modules.js#L24