Invalid JSON/C causes "Unexpected server error" on startup

[HaleTom]

Description

Any syntax error in opencode.jsonc (invalid JSONC, schema validation error) produces an unhelpful error message on startup:

Error: 4 of 6 requests failed: Unexpected server error. Check server logs for details.
Affected startup requests: config.providers, provider.list, app.agents, config.get

The actual error details (line/column of JSONC syntax errors, schema validation issues) are lost because ConfigParse.jsonc() throws JsonError and ConfigParse.effectSchema() throws InvalidError as plain exceptions, which become Effect defects and bubble up as a generic HTTP 500.

Plugins

none

OpenCode version

1.15.10

Steps to reproduce

1. Create opencode.jsonc with invalid JSONC syntax (e.g., missing quote, or brace)
2. Run opencode
3. Observe the generic error message instead of the actual parse/validation error location

Example bad config:

}}{
  "permission": {
    "webfetch": {
      "*": "ask"

Screenshot and/or share link

N/A

Operating System

Linux

Terminal

N/A

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Error: 4 of 5 requests failed: config.providers: Unexpected server error. #27530: Reports the identical error message ("4 of X requests failed: Unexpected server error") on startup — the root cause there was not identified, but it may be the same invalid config issue described here.
• Config loading: silent failures, undocumented fields, and path resolution inconsistencies #28733: Covers related config loading silent failures (invalid fields silently accepted, no user-facing errors), which shares the same theme of config errors not surfacing properly.

If you believe these are distinct issues, feel free to keep this open and link them for cross-reference.