Turbopack Error: Failed to write app endpoint /page

[opensea712]

Turbopack version: d1bd5b58
Next.js version: 16.1.1

Error message:

Failed to write app endpoint /page

Caused by:
- Next.js package not found

Debug info:
- Execution of Project::hmr_version_state failed
- Execution of Project::hmr_version failed
- Execution of VersionedContentMap::get failed
- Execution of VersionedContentMap::get_asset failed
- Execution of VersionedContentMap::compute_entry failed
- Execution of *emit_assets failed
- Execution of all_assets_from_entries_operation failed
- Execution of *all_assets_from_entries failed
- Execution of endpoint_output_assets_operation failed
- Execution of <AppEndpoint as Endpoint>::output failed
- Failed to write app endpoint /page
- Execution of AppEndpoint::output failed
- Execution of AppEndpoint::app_page_entry failed
- Execution of *get_app_page_entry failed
- Execution of AppProject::rsc_module_context failed
- Execution of *ModuleAssetContext::new failed
- Execution of *AppProject::get_rsc_transitions failed
- Execution of AppProject::ecmascript_client_reference_transition failed
- Execution of *NextEcmascriptClientReferenceTransition::new failed
- Execution of AppProject::ssr_transition failed
- Execution of *FullContextTransition::new failed
- Execution of AppProject::ssr_module_context failed
- Execution of AppProject::shared_transition failed
- Execution of *FullContextTransition::new failed
- Execution of AppProject::shared_module_context failed
- Execution of *ModuleAssetContext::new failed
- Execution of get_server_resolve_options_context failed
- Execution of get_next_server_import_map failed
- Next.js package not found

[lMedeirosl]

This seems less like a missing dependency and more like a failure in constructing the Next.js server import map during the RSC/SSR transition phase.
The key failure point is get_next_server_import_map, which suggests the resolver cannot build a consistent module graph for the next package rather than the package being physically absent.
This happens, for example, when node_modules resolution is partially corrupted or Turbopack’s internal project state is inconsistent during HMR initialization
A clean reinstall often resolves it, but if reproducible, it likely points to a resolver state bug rather than a user environment issue.