E0001 — Module not found

What it means

The require() call references a module name that doesn't exist in neoc's registry.

Common causes

• Typo in module name (lib:jsn instead of lib:json)
• Wrong namespace (std:json instead of lib:json)
• Module not available in this neoc version

Example

-- This will produce E0001:
local json = require("lib:jsn")

require: unknown module "lib:jsn" — did you mean "lib:json"? available: lib:base64, lib:compile, lib:http, lib:ini, lib:json, lib:mime, lib:test, lib:vcr

How to fix

Check the module name against the available modules. The error message includes a "did you mean" suggestion when a close match exists, and lists all available modules in the namespace.

Module namespaces

Namespace	Purpose
std:*	Mirrors Rust standard library
lib:*	Blessed gap-fillers and custom modules
vnd:*	Vendored crates (name matches upstream crate)