openclaw - 💡(How to fix) Fix [Bug] Logger _meta.hostname always "unknown" on macOS — os.hostname() returns empty string at module-load time [1 pull requests]

Bug Description

The structured JSON log output (/tmp/openclaw/openclaw-YYYY-MM-DD.log) always shows _meta.hostname: "unknown" regardless of the actual system hostname.

Root Cause

The hostname is set as a module-level constant in src/logging/logger.ts:

const HOSTNAME = os.hostname() || "unknown";

This is evaluated once when the logger module is first imported during Gateway startup. The value is then cached for the entire lifetime of the Gateway process.

On macOS, os.hostname() returns an empty string ("") intermittently during the module load phase, likely due to a timing/race condition in Node.js ESM module resolution. After the Gateway has fully started, os.hostname() works correctly — but the module-level constant is never re-evaluated.

Evidence

• The log file contains entries from three different hostname values across restart cycles:
  • "unknown" — 7017 entries (core subsystems: gateway/ws, diagnostic, plugins)
  • "192.168.1.5" — 97 entries (old hostname)
  • "lr-macbook" — 8 entries (new hostname from the weixin plugin, which uses a DIFFERENT logger instance)
• The weixin plugin uses its own logger instance, not the HOSTNAME constant from logger.ts, so it correctly picks up the hostname.
• Running node -e "require(\"os\").hostname()" always returns the correct hostname.

Suggested Fix

Replace the module-level constant with a lazy function so the hostname is resolved at log-write time, not at module-load time:

// Current — evaluated once at module load
const HOSTNAME = os.hostname() || "unknown";

// Fix — evaluated each time a log entry is written
function getHostname(): string {
  const h = os.hostname();
  return h || "unknown";
}

Environment

• OpenClaw v2026.5.12 (f066dd2)
• macOS 12.6 (Darwin 21.6.0, x64)
• Node.js v22.22.0