openclaw - 💡(How to fix) Fix [Bug]: `openclaw sessions --json` hangs when stdout is not a TTY on 2026.4.5 [2 comments, 2 participants]

Summary

openclaw sessions --json hangs indefinitely when stdout is not a TTY on OpenClaw 2026.4.5.

This reproduces consistently on macOS (arm64) with Volta-managed Node. The same machine does not reproduce the issue on 2026.3.28.

Environment

• OpenClaw: 2026.4.5 (3e72c03)
• Previous working version on same machine: 2026.3.28 (f9b1079)
• OS: macOS / Darwin 25.2.0 (arm64)
• Node: v22.22.1
• Install method: Volta-managed CLI

Impact

This breaks non-interactive / automation use of the sessions CLI, including:

• shell redirection
• pipes
• subprocess capture in Python / other runtimes
• cron / scripts / audit tooling

health --json still works under the same non-TTY conditions, so this appears specific to the sessions --json code path rather than a generic JSON-output failure.

Reproduction

The following all hang on 2026.4.5:

openclaw sessions --json > /tmp/sessions.json
openclaw sessions --json | head -n 5
python3 - <<'PY2'
import subprocess
subprocess.run(
    ["openclaw", "sessions", "--json"],
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
    timeout=20,
)
PY2

Control case that succeeds on the same machine:

openclaw health --json > /tmp/health.json

Observed behavior

• sessions --json > file hangs and leaves a 0-byte output file
• sessions --json | head hangs with no output
• subprocess.run(..., stdout=PIPE) hangs until timeout
• no useful stderr is emitted

Expected behavior

openclaw sessions --json should emit JSON and exit normally regardless of whether stdout is a TTY, pipe, redirect target, or captured stream.

Additional note

This looks like a regression in 2026.4.5 rather than a local config/data corruption issue, because:

1. 2026.3.28 works on the same machine
2. 2026.4.5 reproduces the hang in isolated execution
3. other commands such as health --json, config validate, doctor, and gateway status --json still work