Files
PaperClipAI/packages
DottaandClaude Opus 5.5 3374ca54f5 fix(runner): record a runner exit mid-turn as runner loss, and stop the lineage sampler panicking (#20259)
## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - The native runner (`runnerd`) runs each provider turn, and the
server records why a run stopped and what the person can do next
> - When `runnerd` exits during a provider turn, the server saved the
run as `native_provider_terminal_failed`: "The provider session is
permanently unusable", with automatic retries stopped
> - The real cause was the runner process, and the transport already
names it (`native_runner_process_exited`) at the start of the
closed-stream message
> - Separately, the process-lineage sampler added in #19727 panicked on
Linux debug builds when a provider tool started its own session, and
that panic text became the run's visible failure
> - This pull request records a runner exit mid-turn as runner loss, and
reads session IDs without the assertion that panicked
> - The benefit is that a person sees the true cause of a stopped run,
and recovery treats a lost runner like every other runner exit

## Linked Issues or Issue Description

Refs #19727

**What happened**

A chat eval killed only the owned `runnerd` process (SIGKILL) while a
provider tool was running. The run failed with `errorCode:
native_provider_terminal_failed` and the next action "The provider
session is permanently unusable". The error text was `Notification
transport failed closed: native_runner_process_exited: runnerd exited
unexpectedly: paperclip-runnerd panic: panicked at
rustix-1.1.4/src/pid.rs:61:9: assertion failed: raw > 0`. The panic came
from the lineage sampler thread before the kill. It called
`rustix::process::getsid`, which asserts a nonzero session. A kernel
thread, or a process whose session leader is outside the PID namespace,
reports session 0.

**Expected behavior**

A runner process exit is recorded as `native_runner_process_exited`, the
same cause the server already uses for a runner exit outside a turn.
Recovery then applies its normal runner-loss rules (checkpoint evidence,
bounded attempts, cleanup quarantine). The lineage sampler does not
panic, and its diagnostics do not replace the real failure text.

**Steps to reproduce**

1. Start a native OpenCode run on Linux with a debug `runnerd`.
2. Let the agent run a shell tool that starts its own session (for
example a long `node -e` command).
3. Send SIGKILL to the `runnerd` PID only.
4. Read `GET /api/heartbeat-runs/<runId>`: `errorCode` is
`native_provider_terminal_failed` and the error names the rustix panic.

## What Changed

- `nativeSessionFailureSourceCode` returns
`native_runner_process_exited` for a `NativeProviderTerminalFailure`
with code `notification_transport_failed` when its message starts with
`Notification transport failed closed: native_runner_process_exited: `.
Only the runner transport writes that prefix. Other closed-stream causes
stay `native_provider_terminal_failed`.
- `paperclip-process-table` has a new `session(pid)` function. Linux
reads the session field of `/proc/<pid>/stat`. macOS calls `getsid`. A
session of 0 or an error gives `None`.
- `process_lineage` reads sessions through
`paperclip_process_table::session` instead of rustix `getsid`.
- Regression tests: the runner-loss classification (attempts 1 and 3,
and three negative shapes), the stat session parser with a kernel-thread
line, and a live read of this process's session.

## Verification

- `cd server && npx vitest run
src/services/native-runtime/native-session-executor.test.ts -t "runner
process exit that closed|preserves stable provider and runner|model
rejection from a provider terminal|operator-owned through terminal"` (8
passed)
- `cd packages/paperclip-runner/runner && cargo test -p
paperclip-process-table` (macOS: 3 passed; the Linux-only parser tests
run in CI)
- `cd packages/paperclip-runner/runner && cargo test -p
paperclip-runner-core --lib process_lineage` (6 passed)
- End to end: the `recovery.*` chat eval cells that kill `runnerd` are
run against this change on a separate eval branch.

## Risks

- Behavior shift: a runner exit during a turn now follows runner-loss
recovery instead of stopping as a permanent provider failure. Recovery
still decides from durable evidence. Ambiguous state stays terminal, and
an unverified cleanup stays quarantined.
- Previous-release story: no persisted shape changes. Runs saved earlier
with `native_provider_terminal_failed` keep that code. Only new failures
are classified with the new rule.
- The session read on Linux now uses `/proc` instead of a syscall. It
gives the same value, and it reports 0 (now `None`) in the same cases.

## Model Used

- Anthropic Claude Opus 5.5 (`claude-opus-5-5`), via Claude Code with
tool use (shell, file edits).

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-09 06:38:24 -06:00
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