[BUG] Native installer fails with "another process is currently installing" on Linux even after complete cleanup

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The native installer (curl -fsSL https://claude.ai/install.sh | bash) consistently fails with "another process is currently installing Claude" even on a completely clean system with no prior Claude Code installation artifacts.
The error persists even when:

• All Claude-related directories are removed (~/.claude, ~/.local/share/claude*, ~/.local/bin/claude)
• Config files are removed (~/.claude.json, ~/.claude.json.backup)
• No Claude processes are running (ps aux | grep claude shows nothing)
• No lock files exist anywhere (find across /tmp, /var/lock, /run/lock, $XDG_RUNTIME_DIR shows nothing)
• Running with --force flag

What Should Happen?

• --force should override lock checks as documented
• Fresh install on clean system should succeed
• Error and success messages should not contradict each other

Error Messages/Logs

Contradictory output is printed:

✘ Installation failed
Could not install - another process is currently installing Claude. Please try again in a moment.
Try running with --force to override checks
✅ Installation complete!


Using strace, the binary reads /home/user/.claude.json during install. Even when this file doesn't exist, the error persists.
The install.sh script downloads the binary successfully but the binary's internal install subcommand fails:

# From install.sh:
"$binary_path" install ${TARGET:+"$TARGET"}

The --force flag is documented (claude install --help) but does not bypass the phantom lock detection.

Steps to Reproduce

Complete cleanup:

rm -rf ~/.claude ~/.claude.json ~/.claude.json.backup
rm -rf ~/.local/share/claude* ~/.local/bin/claude

Run native installer:

curl -fsSL https://claude.ai/install.sh | bash

Observe failure with "another process" error followed by contradictory "Installation complete!"
Verify claude binary was not installed:

which claude  # Not found

Attempt with --force:

~/.claude/downloads/claude-2.0.64-linux-x64 install --force
Same error occurs.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.64

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

Platform: linux (CachyOS / Arch Linux)
Terminal: Alacritty (Hyprland/Wayland)
Claude Code version: 2.0.64 (attempting fresh install)
Architecture: x86_64

This may be related to #709 (claude-code-action) and #13085 (VS Code extension lock), but differs in that:

• No prior installation exists
• No VS Code extension is involved
• No actual lock file can be found anywhere on the system
• Occurs on fresh install, not update