Colin McDonnell 5aabd1e4a9 fix(action): cap subprocess stdout/stderr retention to prevent RangeError crashes (#680) (#715)
* fix(action): cap subprocess stdout/stderr retention to prevent RangeError crashes (#680)

unbounded `stdoutBuffer += chunk` / `stderrBuffer += chunk` in
`action/utils/subprocess.ts` previously crashed the wrapper with
`RangeError: Invalid string length` once V8's ~1 GiB kMaxLength was
breached on long-lived agent runs. multi-lens opencode Reviews on large
monorepos (e.g. tambo-ai/buildy) hit this consistently — 23 runs in the
last 24h, 100% of Review-mode hard failures on that repo.

- add `retain: "tail" | "none"` to SpawnOptions, defaulting to "tail"
  with an 8 MiB cap. tail-mode prepends a `... [N MiB truncated] ...`
  sentinel so downstream consumers can detect truncation.
- export `TailBuffer` helper for callers that need the same bounded
  accumulator semantics at their own layer.
- wrap stream `data` listeners in try/catch as defense in depth — any
  synchronous throw inside a stream handler is otherwise fatal.
- opencode + claude pass `retain: "none"` (they drain via onStdout /
  onStderr) and switch their own `output` accumulators to TailBuffer.
  their error paths read the agent-layer bounded mirrors instead of
  the now-empty `result.stdout` / `result.stderr`.
- add `failure:string-length-overflow` heuristic to scripts/analyze-logs.ts
  so post-fix recurrences are visible at a glance instead of bucketing
  into `failure:unknown`.
- regression tests cover >1 MiB stderr without crash, retain:"none"
  contract, and TailBuffer truncation semantics.

* fix: avoid TS parameter property syntax in TailBuffer for strip-only node loader

* address review: clarify try/catch scope + lock retain default to "tail"

- the original comment claimed the try/catch caught "any synchronous throw"
  in the data listener, but `options.onStdout?.(chunk)` returns a Promise
  in the agent callers (claude.ts:569, opencode.ts:933) — a throw inside
  an async user callback surfaces as an unhandled Promise rejection, not
  a synchronous exception. reword to describe the actual protection:
  defense-in-depth for synchronous throws in the listener body, which is
  exactly the shape of the original RangeError on `+= chunk`.
- add a test that locks `retain` default to "tail" by spawning without
  the option and asserting `result.stderr` is non-empty. a future refactor
  that flipped the default to "none" would silently break gitAuth,
  package installs, and lifecycle hooks that read result.stderr for
  failure messages, and the rest of the suite wouldn't catch it.
2026-05-13 17:54:28 +00:00
2026-01-16 08:00:16 +00:00
2026-03-12 05:22:51 +00:00
2025-08-27 16:53:48 -07:00
2026-01-19 08:41:56 +00:00
2026-05-13 04:56:01 +00:00
2026-03-12 05:22:51 +00:00

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Pullfrog

Bring your favorite coding agent into GitHub


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What is Pullfrog?

Pullfrog is a GitHub bot that brings the full power of your favorite coding agents into GitHub. It's open source and powered by GitHub Actions.

  • Tag @pullfrog — Tag @pullfrog in a comment anywhere in your repo. It will pull in any relevant context using the action's internal MCP server and perform the appropriate task.
  • Prompt from the web — Trigger arbitrary tasks from the Pullfrog dashboard
  • Automated triggers — Configure Pullfrog to trigger agent runs in response to specific events. Each of these triggers can be associated with custom prompt instructions.
    • issue created
    • issue labeled
    • PR created
    • PR review created
    • PR review requested
    • and more...

Pullfrog is the bridge between your preferred coding agents and GitHub. Use it for:

  • 🤖 Coding tasks — Tell @pullfrog to implement something and it'll spin up a PR. If CI fails, it'll read the logs and attempt a fix automatically. It'll automatically address any PR reviews too.
  • 🔍 PR review — Coding agents are great at reviewing PRs. Using the "PR created" trigger, you can configure Pullfrog to auto-review new PRs.
  • 🤙 Issue management — Via the "issue created" trigger, Pullfrog can automatically respond to common questions, create implementation plans, and link to related issues/PRs. Or (if you're feeling lucky) you can prompt it to immediately attempt a PR addressing new issues.
  • Literally whatever — Want to have the agent automatically add docs to all new PRs? Cut a new release with agent-written notes on every commit to main? Pullfrog lets you do it.

Standalone Usage

You can also use pullfrog/pullfrog as a step in your own workflows. The action exposes a result output that can be consumed by subsequent steps.

Example: Auto-generate release notes on new tags

name: Release
on:
  push:
    tags: ['v*']

permissions:
  contents: write

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Generate release notes
        id: notes
        uses: pullfrog/pullfrog@v0
        with:
          prompt: |
            Generate release notes for ${{ github.ref_name }}.
            Compare commits between this tag and the previous tag.
            Format as markdown: summary paragraph, then ### Features, ### Fixes, ### Breaking Changes sections.
            Omit empty sections. Be concise.
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}

      # write to file to avoid shell escaping issues with special characters
      - name: Create GitHub release
        run: |
          notesfile="$RUNNER_TEMP/release-notes-$GITHUB_RUN_ID.md"
          printf '%s' "$NOTES" > "$notesfile"
          gh release create ${{ github.ref_name }} --title "${{ github.ref_name }}" --notes-file "$notesfile"
        env:
          GH_TOKEN: ${{ github.token }}
          NOTES: ${{ steps.notes.outputs.result }}

Example: Structured Output with Zod Schema

You can force the agent to return structured JSON output by providing a JSON schema. This allows you to reliably parse and use the agent's response in subsequent workflow steps.

You can define your JSON schema directly or uou can use any validation library that converts to JSON Schema. Here's an example using Zod:

name: Release Check
on:
  pull_request:
    types: [closed]

jobs:
  check-release:
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install dependencies
        run: npm install --no-save --no-package-lock zod @actions/core

      - name: Generate Schema
        id: schema
        run: |
          node -e '
            import { z } from "zod";
            import { setOutput } from "@actions/core";
            const schema = z.object({
              version: z.string().describe("Semantic version number (e.g. 1.0.0)"),
              isBreaking: z.boolean().describe("Whether this release contains breaking changes"),
              changelog: z.array(z.string()).describe("List of changes in this release"),
            });
            setOutput("schema", JSON.stringify(z.toJSONSchema(schema)));
          '

      - name: Analyze PR
        id: analysis
        uses: pullfrog/pullfrog@v0
        with:
          prompt: |
            Analyze this PR and determine semantic versioning impact.
            Return a JSON object matching the provided schema.
          output_schema: ${{ steps.schema.outputs.schema }}
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}

      - name: Process Result
        run: |
          # Parse the JSON result using fromJSON()
          echo "Version: ${{ fromJSON(steps.analysis.outputs.result).version }}"
          echo "Breaking: ${{ fromJSON(steps.analysis.outputs.result).isBreaking }}"
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