useRegistryScript uses Object.assign(userOptions?.scriptOptions || {}, options.scriptOptions || {}) to merge script options. Since Object.assign mutates the first argument and userOptions.scriptOptions is a reference to the runtimeConfig object, registry-defined functions like use() get injected directly into runtimeConfig.public.scripts.<key>.scriptOptions. When Nuxt serializes the payload, devalue throws Cannot stringify a function.

Replaced Object.assign with object spread to create a new object instead of mutating the runtimeConfig reference.

This error is present in the latest stable and in the latest beta versions

StackBlitz

CLI Reproduction

git clone --depth 1 --filter=blob:none --sparse https://github.com/onmax/repros.git
cd repros && git sparse-checkout set scripts-devalue-use
cd scripts-devalue-use && pnpm i && pnpm dev
# Visit http://localhost:3000 → 500 error

Verify fix

git sparse-checkout add scripts-devalue-use-fix
cd ../scripts-devalue-use-fix && pnpm i && pnpm dev
# Visit http://localhost:3000 → page renders