Method fetchOriginTrunk

src/node/runtime/SSHRuntime.ts:2974–3015

* Fetch trunk branch from origin into its remote-tracking ref before checkout. * Returns true if fetch succeeded (origin is available for branching).

(
    workspacePath: string,
    trunkBranch: string,
    initLogger: InitLogger,
    abortSignal?: AbortSignal,
    nhp = ""
  )

   * Returns true if fetch succeeded (origin is available for branching).
   */
  private async fetchOriginTrunk(
    workspacePath: string,
    trunkBranch: string,
    initLogger: InitLogger,
    abortSignal?: AbortSignal,
    nhp = ""
  ): Promise<boolean> {
    try {
      initLogger.logStep(`Fetching latest from origin/${trunkBranch}...`);

      const remoteTrackingRefSpec = `+refs/heads/${trunkBranch}:refs/remotes/origin/${trunkBranch}`;
      const fetchCmd = `${nhp}git fetch origin ${shescape.quote(remoteTrackingRefSpec)}`;
      const fetchStream = await this.exec(fetchCmd, {
        cwd: workspacePath,
        timeout: 120, // 2 minutes for network operation
        abortSignal,
      });

      const fetchExitCode = await fetchStream.exitCode;
      if (fetchExitCode !== 0) {
        const fetchStderr = await streamToString(fetchStream.stderr);
        // Branch doesn't exist on origin (common for subagent local-only branches)
        if (fetchStderr.includes("couldn't find remote ref")) {
          initLogger.logStep(`Branch "${trunkBranch}" not found on origin; using local state.`);
        } else {
          initLogger.logStderr(
            `Note: Could not fetch from origin (${fetchStderr}), using local branch state`
          );
        }
        return false;
      }

      initLogger.logStep("Fetched latest from origin");
      return true;
    } catch (error) {
      const errorMsg = getErrorMessage(error);
      initLogger.logStderr(
        `Note: Could not fetch from origin (${errorMsg}), using local branch state`
      );
      return false;
    }
  }

  /**
   * Check if the local <branch> can fast-forward to origin/<branch>.