Bug: Prompts starting with '---' parsed as CLI options — silent launch failure

[c-h-]

Bug: Prompts starting with --- are parsed as CLI options, crashing the launch

Problem

When launching Claude Code via agentctl launch claude-code -p "<prompt>" where the prompt content begins with --- (e.g., YAML frontmatter from a spec file), Claude Code's argument parser interprets --- as an invalid CLI option flag and exits immediately:

error: unknown option '---

The session never starts. agentctl reports success ("Launched session pending-XXXXX") because the process was spawned, but it exits immediately with an arg parse error.

Reproduction

agentctl launch claude-code --cwd /tmp/test -p "---
title: test
---
Build this."

Impact

• Silent failure — agentctl reports success but no work happens
• Discovered after two wasted launches (dashboard-redesign and unified-feed)
• Any prompt containing a spec file with YAML frontmatter will fail

Suggested Fixes

In agentctl (workaround):

• Prefix prompts that start with - with a newline or space to prevent arg parser confusion
• Or write the prompt to a temp file and use --prompt-file if Claude Code supports it

In Claude Code (root cause):

• The --print -p argument should not be parsed for sub-options. Everything after -p should be treated as literal prompt text.

Environment

• agentctl 1.5.2
• Claude Code 2.1.52

[c-h-]

Workaround available in v1.5.2: Use the new --file flag (#95) to avoid passing prompts with YAML frontmatter directly:

# Instead of: agentctl launch claude-code -p "$(cat spec.md)"  # crashes if spec.md starts with ---
# Use:
agentctl launch claude-code --file spec.md -p "Build the spec"

This avoids the arg parser seeing --- as a CLI option.

Root cause still unfixed: The underlying issue (Claude Code's arg parser treating --- in prompt text as an option flag) remains. A proper fix would need to escape or quote the prompt before passing to the adapter, or use a --prompt-file approach if the adapter supports it.

Leaving open to track the root cause fix.

[c-h-]

Fixed in PR #99