Custom Slash Command Not Working on Ubuntu Linux

Bug Description
custom-slash-commands don't work on Ubuntu Linux but it seems to work on my Mac.

I have followed this guide:

Create a project command

mkdir -p .claude/commands
echo "Analyze this code for performance issues and suggest optimizations:" > .claude/commands/optimize.md

On my Mac /optimize shows up as a command. On linux neither /project:optimize nor /optimize shows up. If I type the command fully it still does not work evidenced by this session where I created a greeting command, see the cat at the end:

╭────────────────────────────────────────────────────────────╮
│ ✻ Welcome to Claude Code! │
│ │
│ /help for help, /status for your current setup │
│ │
│ cwd: /home/sebestjcg/PycharmProjects/github/claude-code │
╰────────────────────────────────────────────────────────────╯

※ Tip: Want Claude to remember something? Hit # to add preferences, tools, and instructions to Claude's memory

/greeting

● Hello! I'm Claude Code, ready to help you with your software engineering tasks.

I can assist with:

• Code analysis and debugging
• Feature implementation
• Refactoring and optimization
• Testing and verification
• Git operations
• And much more

What would you like to work on today?

/project:greeting

● I'll help you understand this project. Let me explore the codebase structure and key files to give you an overview.

● List(.)
⎿  Listed 13 paths (ctrl+r to expand)

● Read(README.md)
⎿  Read 42 lines (ctrl+r to expand)

● Read(package.json)
⎿  Error: File does not exist.

● Search(pattern: "*.json")
⎿  Found 1 file (ctrl+r to expand)

● Search(pattern: "src/**/*")
⎿  Found 0 files

● Read(settings.json)
⎿  Read 49 lines (ctrl+r to expand)

● Read(CHANGELOG.md)
⎿  Read 50 lines (ctrl+r to expand)

● Project: Claude Code

Claude Code is Anthropic's official agentic coding tool - a CLI that lives in your terminal and helps developers code faster through natural language commands.

Key Features:

• Agentic coding assistance - Executes routine tasks, explains complex code, handles git workflows
• Terminal-based interface - Works directly in your terminal or IDE
• Natural language commands - Interact through conversational instructions
• GitHub integration - Can be used with @claude mentions on GitHub

Project Structure:

• Core files: README.md, CHANGELOG.md, LICENSE.md, SECURITY.md
• Configuration: settings.json with permissions, MCP servers, and hooks
• Examples: Hook examples in examples/hooks/
• Scripts: PowerShell setup script for Windows DevContainer

Current Setup:

• Version: 1.0.41 (latest based on changelog)
• Installation: npm install -g @anthropic-ai/claude-code
• MCP Integration: Task Master AI server enabled
• Hooks: Sound notification on completion

Key Capabilities:

• Code analysis and debugging
• Feature implementation
• Git workflow management
• File operations and refactoring
• Testing and verification

This appears to be the official Claude Code repository with configuration for development and testing purposes.

! cat .claude/commands/greeting.md
⎿  Say this and do nothing else: Hello World!

Environment Info

• Platform: linux
• Terminal: tmux
• Version: 1.0.41
• Feedback ID: 01cc059c-b23b-4c1e-b29d-532167f97582

Errors

[{"error":"Error: Command failed: /usr/bin/snap --files --hidden /home/user/PycharmProjects/github/claude-code\nerror: unknown flag `files'\n\n    at genericNodeError (node:internal/errors:983:15)\n    at wrappedFn (node:internal/errors:537:14)\n    at ChildProcess.exithandler (node:child_process:414:12)\n    at ChildProcess.emit (node:events:518:28)\n    at ChildProcess.emit (node:domain:489:12)\n    at maybeClose (node:i

Note: Error logs were truncated.

I've just tested this on my Mac and it's working there so this only affects Linux (haven't tested Windows).