paperclipai/paperclip · error · Error

Target worktree database appears to be running (pid ${runnin

Error message

Target worktree database appears to be running (pid ${runningTargetPid}). Stop Paperclip in ${targetEndpoint.rootPath} before reseeding, or re-run with --allow-live-target if you want to override this guard.

What it means

Thrown by runWorktreeReseed when resolveRunningEmbeddedPostgresPid(targetConfig) returns a live pid and --allow-live-target is not set. resolveRunningEmbeddedPostgresPid only applies to embedded-postgres mode targets and reads postmaster.pid, and readRunningPostmasterPid additionally verifies liveness via process.kill(pid, 0). The guard prevents overwriting a running database, which could corrupt data or fail mid-copy. --allow-live-target is the documented escape hatch.

Source

Thrown at cli/src/commands/worktree.ts:3431

    throw new Error(`Source config not found at ${source.configPath}.`);
  }

  const targetConfig = readConfig(targetEndpoint.configPath);
  if (!targetConfig) {
    throw new Error(`Target config not found at ${targetEndpoint.configPath}.`);
  }
  const sourceConfig = readConfig(source.configPath);
  if (!sourceConfig) {
    throw new Error(`Source config not found at ${source.configPath}.`);
  }

  const targetPaths = resolveWorktreeReseedTargetPaths({
    configPath: targetEndpoint.configPath,
    rootPath: targetEndpoint.rootPath,
  });
  const runningTargetPid = resolveRunningEmbeddedPostgresPid(targetConfig);
  if (runningTargetPid && !opts.allowLiveTarget) {
    throw new Error(
      `Target worktree database appears to be running (pid ${runningTargetPid}). Stop Paperclip in ${targetEndpoint.rootPath} before reseeding, or re-run with --allow-live-target if you want to override this guard.`,
    );
  }

  const confirmed = opts.yes
    ? true
    : await p.confirm({
      message: `Overwrite the isolated Paperclip DB for ${targetEndpoint.label} from ${source.label} using ${seedMode} seed mode?`,
      initialValue: false,
    });
  if (p.isCancel(confirmed) || !confirmed) {
    p.log.warn("Reseed cancelled.");
    return;
  }

  if (runningTargetPid && opts.allowLiveTarget) {
    p.log.warning(`Proceeding even though the target embedded PostgreSQL appears to be running (pid ${runningTargetPid}).`);
  }

View on GitHub (pinned to 67001ec6eb)

Solutions

Stop Paperclip in the target worktree (e.g. stop the dev server / agent runtime) and retry.
Re-run with --allow-live-target if you accept the risk of overwriting a live DB.
Check for the live pid with `ps -p <pid>` to confirm which process holds it before deciding.

Example fix

// before
paperclipai worktree reseed --from-config src.json --to /path/to/target
// after (stop the target first)
# in target worktree: stop paperclipai dev, then
paperclipai worktree reseed --from-config src.json --to /path/to/target
// or override the guard
paperclipai worktree reseed --from-config src.json --to /path/to/target --allow-live-target

Defensive patterns

Strategy: validation

Validate before calling

import fs from "node:fs";
import path from "node:path";

function readLivePostmasterPid(dataDir: string): number | null {
  const pidFile = path.resolve(dataDir, "postmaster.pid");
  if (!fs.existsSync(pidFile)) return null;
  const pid = Number(fs.readFileSync(pidFile, "utf8").split("\n")[0]?.trim());
  if (!Number.isInteger(pid) || pid <= 0) return null;
  try { process.kill(pid, 0); return pid; } catch { return null; }
}

// before reseed, read targetConfig.database.embeddedPostgresDataDir and check:
const livePid = readLivePostmasterPid(targetConfig.database.embeddedPostgresDataDir);
if (livePid && !opts.allowLiveTarget) {
  throw new Error(`Stop the target embedded PostgreSQL (pid ${livePid}) before reseeding, or pass --allow-live-target.`);
}

Prevention

Stop `paperclipai dev` and any agent runtime in the target worktree before reseeding.
Script a pre-check using readRunningPostmasterPid semantics (pid alive via process.kill(pid,0)) before invoking reseed.
Use --allow-live-target only when you understand the data-loss risk.

When it happens

Trigger: Calling `worktree reseed` against a target worktree whose embedded PostgreSQL is currently running (the Paperclip server in that worktree is up), without --allow-live-target. The pid in postmaster.pid must belong to a live process.

Common situations: A developer left `paperclipai dev` (or a server) running in the target worktree and tries to reseed it from another terminal. Or a background agent runtime holds the embedded DB open.

Related errors

AI-assisted analysis of paperclipai/paperclip@67001ec6eb (2026-08-12). Data as JSON: /api/errors/d4a7f6a673add312. Report an issue: GitHub.