DYNAMIC_ASYNC_COMPONENT
An async dynamic() source landed on a client component function, which cannot serialize for adoption; the memo rejects (observe + dev; rejects in every tier).
What you saw
- Kind:
ssr - Severity:
error(broken behavior)
The console report opens with [DYNAMIC_ASYNC_COMPONENT] and the message, then an in line naming the owners that enclose the subject, root first, and an at line with the source location when the code was compiled with one.
In a captured artifact the same finding is an event with code: "DYNAMIC_ASYNC_COMPONENT", ownerPath, and loc.
Diagnostics explains each line.
Why it fires
An async dynamic() source resolved to a client component function.
The instance memo serializes its landing for the client to adopt (#3666) and a function has no encoding, so the memo rejects with this message in every tier (the nearest <Errored> / onError contains it) instead of leaving the client pending or re-running the source under the boundary — the phantom-fallback bug the adoption fixed.
data.component names the function.
The server runtime reports on the same channel, with the same in <App> › <Page> line.
Two groups.
Findings (SSR_RENDER_ERROR_CONTAINED, SSR_SUBTREE_ABANDONED, SSR_STREAM_ABANDONED, LATE_HEADER_WRITE, DYNAMIC_ASYNC_COMPONENT, SERVER_ERROR_SANITIZED, FRAME_MARKER_CORRUPTED) are facts about a render that exist in observe builds too — an APM sees them in production; in dev they print.
Checks (the rest, SSR_BOUNDARY_WATERFALL and SSR_CLIENT_CONTENT_MASKED included) are dev-only guidance.
A captured artifact from a server render carries both.
How to fix it
Move the async upstream (a createAsync/createMemo the source reads synchronously) or use lazy() for code; a server component or a tag name may stay async.
In tests
captureArtifact from @solidjs/diagnostics runs a scenario with the diagnostics channel open and returns the events it saw.
expectNoDiagnostics(artifact) fails while DYNAMIC_ASYNC_COMPONENT is among them, with the events as evidence; after the fix, the code is gone from artifact.diagnostics.
Check for regressions in tests shows the loop and the Vitest matcher form.
Learn more
- Diagnostics: every code, with its kind, severity, and trigger.
- Debugging reactivity: how to read a report and what each group of codes points at.