Sandbox Npm Install
GitHubOfficialFirst committed by GeekTrainerDistributed by GitHub
- Skill
- Workflow
- Software development
- MIT
- Low risk
- Has scripts
AutoGineer summary
Written by AutoGineer from the skill’s own files, not by the author
This skill provides a robust method for installing npm dependencies within Docker sandbox environments that use virtiofs mounts. Because certain native binaries (such as esbuild, rollup, and lightningcss) fail when executed from virtiofs-mounted directories due to mmap alignment issues, this workflow automates the process of installing packages on the container's local ext4 filesystem and symlinking them back to the workspace. This ensures stability for development and build processes while maintaining compatibility with the host-synced workspace.
What it does
- Copies configuration files to a local ext4 directory
- Executes npm installation on the local filesystem to avoid virtiofs issues
- Creates symlinks to map the local node_modules back into the workspace
- Verifies the integrity of critical native binaries post-installation
- Supports optional installation of Playwright browsers for testing
- Provides troubleshooting guidance for common binary crash errors
When to use it
- When working in a Docker sandbox with a virtiofs-mounted workspace
- When encountering SIGILL, SIGSEGV, or mmap errors during npm package execution
- When setting up a new project or after modifying package.json or package-lock.json
- When native binaries like esbuild or rollup fail to run correctly
Advantages
- Prevents non-deterministic crashes caused by virtiofs file system limitations
- Automates the complex process of local installation and symlinking
- Ensures native binaries function correctly in containerized development environments
- Reduces manual intervention when managing dependencies in sandboxed workspaces
Usage examples
- “Install my project dependencies in the sandbox.”
- The agent executes the installation script, which installs packages to the local ext4 filesystem and symlinks node_modules, ensuring native binaries run without crashing.
- “My build is failing with a SIGILL error, how do I fix it?”
- The agent identifies the likely cause as a virtiofs issue and runs the installation script to re-install dependencies on the local filesystem.
Install
Download the skill as a ZIP:
https://mp-staging.autogineer.com/agent-skills/github/sandbox-npm-install/downloadUnzip it into the cross-client skills folder of your project:
mkdir -p .agents/skills && unzip sandbox-npm-install.zip -d .agents/skills
Documentation by GeekTrainer
Sandbox npm Install
When to Use This Skill
Use this skill whenever:
You need to install npm packages for the first time in a new sandbox session
package.jsonorpackage-lock.jsonhas changed and you need to reinstallYou encounter native binary crashes with errors like
SIGILL,SIGSEGV,mmap, orunaligned sysNoHugePageOSThe
node_modulesdirectory is missing or corrupted
Prerequisites
A Docker sandbox environment with a virtiofs-mounted workspace
Node.js and npm available in the container
A
package.jsonfile in the target workspace
Background
Docker sandbox workspaces are typically mounted via virtiofs (file sync between the host and Linux VM). Native Go and Rust binaries (esbuild, lightningcss, rollup, etc.) crash with mmap alignment failures when executed from virtiofs on aarch64. The fix is to install on the container's local ext4 filesystem and symlink back into the workspace.
Step-by-Step Installation
Run the bundled install script from the workspace root:
bash scripts/install.shCommon Options
| Option | Description |
|---|---|
--workspace <path> | Path to directory containing package.json (auto-detected if omitted) |
--playwright | Also install Playwright Chromium browser for E2E testing |
What the Script Does
Copies
package.json,package-lock.json, and.npmrc(if present) to a local ext4 directoryRuns
npm ci(ornpm installif no lockfile) on the local filesystemSymlinks
node_modulesback into the workspaceVerifies known native binaries (esbuild, rollup, lightningcss, vite) if present
Optionally installs Playwright browsers and system dependencies (uses
sudowhen available)
If verification fails, run the script again — crashes can be intermittent during initial setup.
Post-Install Verification
After the script completes, verify your toolchain works. For example:
npm test # Run project tests
npm run build # Build the project
npm run dev # Start dev serverImportant Notes
The local install directory (e.g.,
/home/agent/project-deps) is container-local and is NOT synced back to the hostThe
node_modulessymlink appears as a broken link on the host — this is harmless sincenode_modulesis typically gitignoredRunning
npm ciornpm installon the host naturally replaces the symlink with a real directoryAfter any
package.jsonorpackage-lock.jsonchange, re-run the install scriptDo NOT run
npm ciornpm installdirectly in the mounted workspace — native binaries will crash
Troubleshooting
| Problem | Solution |
|---|---|
SIGILL or SIGSEGV when running dev server | Re-run the install script; ensure you're not running npm install directly in the workspace |
node_modules not found after install | Check that the symlink exists: ls -la node_modules |
| Permission errors during install | Ensure the local deps directory is writable by the current user |
| Verification fails intermittently | Run the script again — native binary crashes can be non-deterministic on first load |
Vite Compatibility
If your project uses Vite, you may need to allow the symlinked path in server.fs.allow. Add the symlink target's parent directory (e.g., /home/agent/project-deps/) to your Vite config so that Vite can serve files through the symlink.
Files
- ATTRIBUTION.mdAdded by AutoGineer877 B
- LICENSELicence file added by AutoGineer1.0 KiB
- SKILL.md3.7 KiB
- scripts/install.shScript5.5 KiB
scripts/install.sh
#!/usr/bin/env bash
set -euo pipefail
# Sandbox npm Install Script
# Installs node_modules on local ext4 filesystem and symlinks into the workspace.
# This avoids native binary crashes (esbuild, lightningcss, rollup) on virtiofs.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
# Local ext4 base directory where node_modules is installed to avoid virtiofs crashes.
# Change this path if your sandbox uses a different local filesystem location.
readonly DEPS_BASE="/home/agent/project-deps"
WORKSPACE_CLIENT=""
INSTALL_PLAYWRIGHT="false"
usage() {
cat <<EOF
Usage: $(basename "$0") [options]
Options:
--workspace <path> Client workspace containing package.json
--playwright Install Playwright Chromium browser
--help Show this help message
Examples:
bash scripts/install.sh
bash scripts/install.sh --workspace app/client --playwright
EOF
}
while [[ $# -gt 0 ]]; do
case "$1" in
--workspace)
if [[ -z "${2:-}" ]]; then
echo "Error: --workspace requires a path argument"
usage
exit 1
fi
WORKSPACE_CLIENT="$2"
shift 2
;;
--playwright)
INSTALL_PLAYWRIGHT="true"
shift
;;
--help|-h)
usage
exit 0
;;
*)
echo "Unknown option: $1"
usage
exit 1
;;
esac
done
if [[ -z "$WORKSPACE_CLIENT" ]]; then
if [[ -f "$PWD/package.json" ]]; then
WORKSPACE_CLIENT="$PWD"
elif [[ -f "$REPO_ROOT/package.json" ]]; then
WORKSPACE_CLIENT="$REPO_ROOT"
fi
fi
if [[ -n "$WORKSPACE_CLIENT" ]]; then
WORKSPACE_CLIENT="$(cd "$WORKSPACE_CLIENT" 2>/dev/null && pwd || true)"
fi
if [[ -z "$WORKSPACE_CLIENT" || ! -f "$WORKSPACE_CLIENT/package.json" ]]; then
echo "Could not find a valid workspace client path containing package.json."
echo "Use --workspace <path> to specify it explicitly."
exit 1
fi
echo "=== Sandbox npm Install ==="
echo "Workspace: $WORKSPACE_CLIENT"
# Derive a unique subdirectory from the workspace path relative to the repo root.
# e.g. /repo/apps/web -> apps-web, /repo -> <repo-basename>
REL_PATH="${WORKSPACE_CLIENT#"$REPO_ROOT"}"
REL_PATH="${REL_PATH#/}"
if [[ -z "$REL_PATH" ]]; then
REL_PATH="$(basename "$REPO_ROOT")"
fi
# Sanitize: replace path separators with hyphens
DEPS_SUBDIR="${REL_PATH//\//-}"
DEPS_DIR="${DEPS_BASE}/${DEPS_SUBDIR}"
echo "Deps dir: $DEPS_DIR"
# Step 1: Prepare local deps directory
echo "→ Preparing $DEPS_DIR..."
if [[ -z "$DEPS_DIR" || "$DEPS_DIR" != "${DEPS_BASE}/"* ]]; then
echo "ERROR: DEPS_DIR ('$DEPS_DIR') is not under DEPS_BASE ('$DEPS_BASE'). Aborting."
exit 1
fi
rm -rf "$DEPS_DIR"
mkdir -p "$DEPS_DIR"
chmod 700 "$DEPS_DIR"
cp "$WORKSPACE_CLIENT/package.json" "$DEPS_DIR/"
# Copy .npmrc if present (needed for private registries / scoped packages)
# Permissions restricted to owner-only since .npmrc may contain auth tokens
if [[ -f "$WORKSPACE_CLIENT/.npmrc" ]]; then
cp "$WORKSPACE_CLIENT/.npmrc" "$DEPS_DIR/"
chmod 600 "$DEPS_DIR/.npmrc"
fi
if [[ -f "$WORKSPACE_CLIENT/package-lock.json" ]]; then
cp "$WORKSPACE_CLIENT/package-lock.json" "$DEPS_DIR/"
INSTALL_CMD=(npm ci)
else
echo "! package-lock.json not found; falling back to npm install"
INSTALL_CMD=(npm install)
fi
# Step 2: Install on local ext4
echo "→ Running ${INSTALL_CMD[*]} on local ext4..."
cd "$DEPS_DIR" && "${INSTALL_CMD[@]}"
# Step 3: Symlink into workspace
echo "→ Symlinking node_modules into workspace..."
cd "$WORKSPACE_CLIENT"
rm -rf node_modules
ln -s "$DEPS_DIR/node_modules" node_modules
has_dep() {
local dep="$1"
node -e "
const pkg=require(process.argv[1]);
const deps={...(pkg.dependencies||{}),...(pkg.devDependencies||{}),...(pkg.optionalDependencies||{})};
process.exit(deps[process.argv[2]] ? 0 : 1);
" "$WORKSPACE_CLIENT/package.json" "$dep"
}
verify_one() {
local label="$1"
shift
if "$@" >/dev/null 2>&1; then
echo " ✓ $label OK"
return 0
fi
echo " ✗ $label FAIL"
return 1
}
# Step 4: Verify native binaries when present in this project
echo "→ Verifying native binaries..."
FAIL=0
if has_dep esbuild; then
verify_one "esbuild" node -e "require('esbuild').transform('const x: number = 1',{loader:'ts'}).catch(()=>process.exit(1))" || FAIL=1
fi
if has_dep rollup; then
verify_one "rollup" node -e "import('rollup').catch(()=>process.exit(1))" || FAIL=1
fi
if has_dep lightningcss; then
verify_one "lightningcss" node -e "try{require('lightningcss')}catch(_){process.exit(1)}" || FAIL=1
fi
if has_dep vite; then
verify_one "vite" node -e "import('vite').catch(()=>process.exit(1))" || FAIL=1
fi
if [ "$FAIL" -ne 0 ]; then
echo "✗ Binary verification failed. Try running the script again (crashes can be intermittent)."
exit 1
fi
# Step 5: Optionally install Playwright
if [[ "$INSTALL_PLAYWRIGHT" == "true" ]]; then
echo "→ Installing Playwright browsers..."
if [[ "${EUID:-$(id -u)}" -eq 0 ]]; then
npx playwright install --with-deps chromium
elif command -v sudo &>/dev/null && sudo -n true 2>/dev/null; then
# Non-root but passwordless sudo available — install browsers then system deps
npx playwright install chromium
sudo npx playwright install-deps chromium
else
npx playwright install chromium
echo "⚠ System dependencies not installed (no root/sudo access)."
echo " Playwright tests may fail. Run: sudo npx playwright install-deps chromium"
fi
fi
echo ""
echo "=== ✓ Sandbox npm install complete ==="
echo "Run 'npm run dev' to start the dev server."
Requirements and compatibility
Written for: GitHub Copilot
Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta
“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.
Needs: Needs Node.js
Security
What our scanner noticed· Low risk
- Scripts that your agent may run
This skill includes scripts that your agent may run. Read them before you use it.
A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.
Attribution and licence
- First committed by
GeekTrainer
- Publisher
- GitHub (Official)
- Distributed by
- GitHub
- Source
- github/awesome-copilot · skills/sandbox-npm-install · commit 797337f
- Licence
- MIT License (redistribution allowed)
- LICENSE (added by AutoGineer from LICENSE)
- ATTRIBUTION.md (written by AutoGineer)
- Synced
- Contributors
- GeekTrainer
AutoGineer is not affiliated with or endorsed by GeekTrainer or GitHub.
Download ZIP
The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download sandbox-npm-install.zip