[cscheid]

Fixes #847

What

Calling pandoc.read(text, "markdown") from an {lmd} cell or a Lua filter on text containing a pipe table printed one unformatted [TOP-LEVEL MISSING NODE] Warning: Unhandled node kind: - line per delimiter-row dash to stderr. Two independent causes, both fixed:

1. The Lua binding pointed the reader's verbose trace at stderr. readers::qmd::read takes an output stream that is a pampa -v trace, not a diagnostic channel; every pipeline caller sinks it. pandoc_read in lua/readwrite.rs was the only production caller passing std::io::stderr(). It now passes VerboseOutput::Sink, like lua/config_value.rs. This alone closes the issue.
2. Four marker tokens had no arm in the tree-sitter dispatch. The -, pipe_table_align_left and pipe_table_align_right children of pipe_table_delimiter_cell, and the ![ opener of pandoc_image, are consumed by their parent processors by node name but fell through to the catch-all, which wrote the trace line. They now get explicit arms in the existing marker-token pattern (atx markers, task-list markers, math delimiters). Behavior-preserving: the catch-all already returned the same IntermediateUnknown. After this pampa -v is quiet on well-formed input, so the catch-all means what it says.

Tests (written first, both red on the unfixed tree)

• crates/pampa/tests/integration/test_trace_buffer_silence.rs: the reader's trace buffer stays empty for a pipe table (all four alignments, alignments asserted) and an inline image.
• crates/quarto/tests/integration/pandoc_read_stderr_e2e.rs: q2 render of the issue's repro leaves stderr free of the trace lines and still emits both tables.

Also checked on the unfixed tree that hyphens in text, a - b, link destinations and titles, autolinks, code spans, math, list markers and thematic breaks never produce a bare - node, so the new - arm only ever sees delimiter-row dashes (probe and output under claude-notes/plans/pandoc-read-delimiter-dash-noise-investigation/).

Out of scope, filed as follow-ups

• bd-fwswbxnl: pandoc.read still discards the reader's real diagnostics (the third tuple element).
• bd-yi613i1r: make the dispatch catch-all visible to tests instead of only to pampa -v.

Plan: claude-notes/plans/2026-10-15-pandoc-read-delimiter-dash-noise.md. cargo xtask verify --skip-hub-build green on the branch.

🤖 Generated with Claude Code

[posit-snyk-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.