@workflow/ai@4.1.2 triggers SWC "failed to read input source map" errors during Nitro dev builds

[waldhari1]

Summary

Every nitro dev build prints SWC sourcemap errors against four .js files inside @workflow/ai/dist/ (providers/anthropic.js, agent/durable-agent.js, agent/stream-text-iterator.js, agent/do-stream-step.js). Builds still succeed, but the noise is constant on every reload.

Environment

• @workflow/ai: 4.1.2
• @workflow/core (peer): 4.2.4 (resolved by pnpm — note the minor split)
• ai: 5.0.161
• zod: 3.25.76
• Build tool: Nitro dev (rollup builder, nitro-dev preset, compatibility date 2024-12-26)
• Node: 22.x, pnpm install
• Stack trace points to crates/swc/src/lib.rs:398

Error output (representative)

ERROR  failed to read input source map: failed to find input source map file
"anthropic.js.map" in "node_modules/.../@workflow/ai/dist/providers/anthropic.js"
file as either ".../anthropic.js.map" or with appended .map
  at crates/swc/src/lib.rs:398

Repeats for the four files listed above.

What I verified locally

The .map files are present and valid:

File	.js size	.js.map size	.map valid JSON?
dist/providers/anthropic.js	239 B	582 B	yes
dist/agent/durable-agent.js	35,364 B	79,787 B	yes
dist/agent/stream-text-iterator.js	19,123 B	31,488 B	yes
dist/agent/do-stream-step.js	31,410 B	51,204 B	yes

Each .js ends with //# sourceMappingURL=<name>.js.map and the corresponding .map parses with all expected keys (version, file, sources, mappings, sourcesContent).

The sources field points at the TypeScript originals (e.g. ../../src/providers/anthropic.ts), which are not included in the published tarball. That may be what SWC is actually complaining about even though the message says "find input source map file" — i.e. the map exists, but the upstream sources it references can't be resolved.

Reproduction

1. Install @workflow/ai@4.1.2 in a Nitro-based app (we hit this in apps/unified-api/ running pnpm dev:api through Turbo).
2. Start the dev server.
3. Errors print on every build/reload.

Impact

Cosmetic — builds and the dev server still work. But it's noisy enough to drown out real errors and shows up on every restart across our team.

Asks

1. Either ship the src/ directory in the tarball alongside dist/ so the maps' sources resolve, or strip //# sourceMappingURL= comments from the published .js files (or inline the sourcesContent so external resolution isn't needed — the maps already include sourcesContent, so this should already work; happy to dig further if that's surprising).
2. Confirm whether @workflow/ai@4.1.2 is intended to track @workflow/core@4.2.4, or whether a synchronized 4.2.x release of @workflow/ai is coming.