/insights generates empty report ("No insights generated") despite populated session-meta; facets/ never created

What happened

Running /insights produces an empty report — every section renders "No data" and the summary says "No insights generated" — even though there is plenty of session history to analyze.

At-a-glance header from the generated report:

72 sessions total · 67 analyzed · 1,310 messages · 986h · 18 commits (2026-07-06 to 2026-08-04)

So the command counts the sessions and claims 67 were "analyzed", but then generates zero insights.

Diagnosis

claude dug into ~/.claude/usage-data/:

• session-meta/ — 70 valid JSON files, spanning the full range (2026-07-06 → 2026-08-04), 1,314 user messages total, with real activity (individual sessions of 300–1,200+ messages, multiple git commits, non-zero durations). Input data is complete and rich.
• facets/ — does not exist. The report references facets, but the directory is never created/populated.
• report.html — every section is literally No data; only the <h1>Claude Code Insights</h1> header renders.

So the failure is entirely in the facet / insight-synthesis stage — the per-session aggregate metadata is fine, but nothing downstream produces facets or insights from it. The "67 analyzed" count is misleading given zero output.

Expected

With 70 sessions of populated metadata and 1,300+ messages, /insights should generate a non-empty report (or, if it genuinely can't, explain why rather than silently emitting "No data" everywhere).

Also

• /insights appears to accept no arguments (no date-range / scope flag, no force-refresh). If facet generation can silently produce nothing, there's no user-facing way to re-trigger or scope it. A --force / regenerate path would help.

Environment

• Claude Code 2.1.220
• Platform: macOS (darwin, arm64)

Repro

1. Accumulate normal session history (weeks of usage).
2. Run /insights.
3. Observe report with "No insights generated" / all sections "No data", and an empty/absent ~/.claude/usage-data/facets/.