Description

Description

PR: fix(sandbox): restrict /sandbox to read-only via Landlock

Using the security/read-only-sandbox-filesystem branch, running nemoclaw onboard fails during sandbox creation (step 6/8) with:

/usr/local/bin/nemoclaw-start: line 203: _SANDBOX_HOME: unbound variable

The variable _SANDBOX_HOME is referenced at 3 locations in scripts/nemoclaw-start.sh (lines 178, 203, and 246), but it is never defined anywhere in the file. Because the script uses set -euo pipefail, the unbound variable causes an immediate exit.

Environment

• OS: Ubuntu (Linux 6.17.0-1008-nvidia, aarch64)
• Node.js: v22.22.2
• Docker: 29.1.3
• NemoClaw: v0.1.0
• Branch: security/read-only-sandbox-filesystem (commit 0d85225)

Steps to Reproduce

1. Clone the repo:

   git clone -b security/read-only-sandbox-filesystem https://github.com/prekshivyas/NemoClaw.git

2. Install dependencies and build:

   npm install && npm link && cd nemoclaw && npm install && npm run build && cd ../nemoclaw-blueprint && uv sync && cd ..

3. Run nemoclaw onboard and complete steps 1-5 (preflight, gateway, inference, provider, messaging).
4. At step 6, enter a sandbox name and wait for image build and sandbox creation.
5. Sandbox creation fails with _SANDBOX_HOME: unbound variable.

Logs

[SECURITY] CAP_SETPCAP not available -- runtime already restricts capabilities
Setting up NemoClaw...
[gateway] Running as non-root (uid=998) -- privilege separation disabled
/usr/local/bin/nemoclaw-start: line 203: _SANDBOX_HOME: unbound variable
Error:   x ssh exited with status exit status: 1
  Try:  openshell sandbox list        # check gateway state
  Hint: sandbox creation started but the create stream did not finish cleanly.
  Recovery: nemoclaw onboard --resume

Analysis

_SANDBOX_HOME is used in three places but never assigned:

• Line 178: export_gateway_token() - cleanup stale tokens from rc files
• Line 203: export_gateway_token() - persist token to .bashrc/.profile
• Line 246: install_configure_guard() - guard openclaw configure

The variable likely needs to be defined as _SANDBOX_HOME="/sandbox", or resolved dynamically via getent passwd sandbox, before these references are used.

Expected Behavior

nemoclaw onboard should complete successfully.

Actual Behavior

nemoclaw onboard gets stuck at the sandbox creation step and exits with _SANDBOX_HOME: unbound variable.

Bug Details

[NVB# 6059349]

[NVB#6059349]