Overlay - Development Session Management

Overview

The overlay command manages development sessions that enable live editing of justfiles by creating symlinks from the repository to /usr/share/bazzite-ai/just/. This allows testing changes without rebuilding the OS image.

Key Concept: On immutable OSTree systems (Bazzite-AI, Silverblue), /usr is read-only. Overlay mode temporarily unlocks it. On traditional systems (Fedora, CentOS), symlinks provide the same live-editing capability.

This is a development command - run with just from the repository root, not ujust.

Quick Reference

Note: just overlay refresh automatically enables the overlay if not active - this is the recommended primary command.

Parameters

just overlay ACTION

Overlay Commands

Refresh (Recommended)

just overlay refresh

Auto-enables if needed, then regenerates imports. Use this as your primary command.

1. Checks if overlay/symlinks are active
2. If NOT active → automatically runs enable first
3. Regenerates 60-custom.just import file
4. Shows success message

Check Status

just overlay check

Shows current status:

• Immutable OS: Whether overlay mode is active
• Traditional OS: Whether symlinks are configured
• Target repository path

Enable (Manual)

just overlay enable

Manually bootstraps overlay session:

1. Activates overlay mode (OSTree) or creates symlinks (traditional)
2. Detects repository location automatically
3. Sets up symlinks to /usr/share/bazzite-ai/just/
4. Generates 60-custom.just import file
5. Requires sudo (handles internally)

Note: You rarely need this directly - just overlay refresh auto-enables.

System Info

just overlay info

Shows detailed information about:

• OS type (immutable vs traditional)
• Current overlay status
• Repository path
• Symlink targets

OS Type Detection

Common Workflows

Initial Development Setup

# 1. Clone repository
git clone <repo-url> && cd bazzite-ai

# 2. Start overlay testing (auto-enables if needed)
just overlay refresh

# 3. Make changes to justfiles
vim just/bazzite-ai/my-feature.just

# 4. Test immediately with ujust
ujust my-feature

# 5. If adding new files, refresh again
just overlay refresh

After Reboot (Immutable OS Only)

# Overlay resets on reboot - just run refresh
just overlay refresh

# It auto-enables, then refreshes
# Your git commits persist, overlay changes don't

Testing a New Command

# 1. Create/edit the justfile
vim just/bazzite-ai/new-command.just

# 2. Refresh to pick up new file
just overlay refresh

# 3. Test the command
ujust new-command

Troubleshooting

Overlay Not Active After Enable

Symptom: just overlay check shows "Normal immutable mode"

Cause: Overlay activation failed

Fix:

# Check if rpm-ostree unlock succeeded
sudo rpm-ostree status | grep -i unlock

# If not, try manual unlock
sudo rpm-ostree usroverlay

# Then refresh
just overlay refresh

Symlinks Not Working

Symptom: Changes to justfiles not reflected in ujust output

Cause: Symlinks not properly created or 60-custom.just not regenerated

Fix:

# Check symlink status
ls -la /usr/share/bazzite-ai/just/

# Refresh (auto-enables if needed)
just overlay refresh

Command Not Found After Adding File

Symptom: New recipe not available in ujust --list

Cause: 60-custom.just needs regeneration

Fix:

just overlay refresh

Permission Denied

Symptom: sudo: a terminal is required

Cause: Running in non-interactive mode without passwordless sudo

Fix:

# Enable passwordless sudo first
ujust config passwordless-sudo enable

# Then retry
just overlay refresh

Cross-References

• Related Skills: test (runtime verification), build (image building)
• Configuration: ujust config passwordless-sudo enable for sudo access
• Documentation: See architecture docs for overlay internals

When to Use This Skill

Use when the user asks about:

• "enable overlay", "start testing session", "development mode"
• "test my changes", "live reload justfiles"
• "overlay not working", "symlinks not configured"
• "refresh overlay", "pick up new files"
• "just overlay" (any overlay command)