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UnknownTracked since May 19, 2026

cc-connect sessions fail on long single-line stdout output

The report identifies a single primary defect: cc-connect’s agent stdout read loops for codexSession and claudeSession can terminate a live session when output contains a line over ~64KB, matching the Go `bufio.Scanner` token-length failure mode. Repeated logs show both sessions returning `bufio.Scanner: token too long` and dropping the session after long JSON/JSONL lines.

cc-connectbufio.ScannercodexSessionclaudeSession

What Happened

  • The report identifies a single primary defect: cc-connect’s agent stdout read loops for codexSession and claudeSession can terminate a live session when output contains a line over ~64KB, matching the Go `bufio.Scanner` token-length failure mode. Repeated logs show both sessions returning `bufio.Scanner: token too long` and dropping the session after long JSON/JSONL lines.
  • The report identifies a single primary defect: cc-connect’s agent stdout read loops for codexSession and claudeSession can terminate a live session when output contains a line over ~64KB, matching the Go `bufio.Scanner` token-length failure mode. Repeated logs show both sessions returning `bufio.Scanner: token too long` and dropping the session after long JSON/JSONL lines.
  • 1 evidence item attached for review.

What is Different

Before

Scattered source updates, isolated context, and manual follow-up across multiple feeds.

Now

This issue contributes a concrete correctness finding: the stream parser path has an implicit hard limit from Go scanner defaults and lacks resilience for oversized lines, so the suggested fix is to expand/parameterize the buffer or replace scanner-based line reading with a streaming approach that can warn and continue on overlong non-JSON lines instead of terminating the session.

Why Track This

Why It Matters

Operators running cc-connect with codexSession or claudeSession can lose in-progress agent sessions when tools emit large one-line outputs, which can break prompts, pipelines, or long autonomous tasks that rely on uninterrupted stdout streaming. The underlying mechanism is the read loop’s use of `bufio.Scanner` with its default token cap, so watch for whether implementations switch to bounded, configurable handling that degrades safely (warning/truncation/fallback) without dropping the whole session, while also checking for any memory-growth risks from raising limits too aggressively.

Impact

Operators running cc-connect with codexSession or claudeSession can lose in-progress agent sessions when tools emit large one-line outputs, which can break prompts, pipelines, or long autonomous tasks that rely on uninterrupted stdout streaming. The underlying mechanism is the read loop’s use of `bufio.Scanner` with its default token cap, so watch for whether implementations switch to bounded, configurable handling that degrades safely (warning/truncation/fallback) without dropping the whole session, while also checking for any memory-growth risks from raising limits too aggressively.

What To Watch Next

  • Watch whether cc-connect becomes a repeated pattern.
  • Track follow-up changes around AI Debugging and Error Localization.
  • Compare future signals against this evidence trail.
  • Re-check risk flags: single_line_output_terminates_sessions, hardcoded_scanner_limit_without_config.
Open Topic TimelineOpen Technical EventOpen Original Sourcesingle_line_output_terminates_sessions / hardcoded_scanner_limit_without_config / truncation_or_skip_path_missing_for_overlong_lines / memory_growth_risk_when_buffer_expands

Supporting Evidence

GITHUB ISSUEHigh Trust

cc-connect sessions fail on long single-line stdout output

`codexSession: scanner error error="bufio.Scanner: token too long"` and `agent error error="read stdout: bufio.Scanner: token too long"` occur when agents emit a large single-line JSON/JSONL payload.