[Bug] Install subcommand downloads wrong architecture on Apple Silicon

claude install Command Installs Wrong Architecture on Apple Silicon

Summary

The claude install subcommand incorrectly installs the x86_64 binary on my M1 Apple Silicon MacBook, even when executed from an ARM64 binary in a native ARM64 shell.

Environment

• OS: macOS (Apple Silicon)
• Architecture: arm64 (verified with uname -m)
• Terminal: iTerm2 (native ARM, "Open using Rosetta" unchecked)
• Shell: bash (native ARM)
• Claude Code Version: 2.0.67 (from manifest)

Steps to Reproduce

1. In a native ARM64 terminal (verify with uname -m → arm64):

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

1. The script correctly:

• Detects darwin-arm64 platform
• Downloads ARM binary: {GCS_BUCKET}/2.0.67/darwin-arm64/claude
• Verifies ARM checksum: 4b5709f0b799650445da3df46025f600f6ddcc65f2c9857d2c83eb986c343ff0
• Downloaded binary is ARM64: file ~/.claude/downloads/claude-2.0.67-darwin-arm64 → Mach-O 64-bit executable arm64

1. Script runs: ~/.claude/downloads/claude-2.0.67-darwin-arm64 install

1. Check installed binary:

``bash
file ~/.local/bin/claude
``

Expected Behavior

~/.local/bin/claude should be Mach-O 64-bit executable arm64

Actual Behavior

~/.local/bin/claude is Mach-O 64-bit executable x86_64

Running claude shows:

warn: CPU lacks AVX support, strange crashes may occur. Reinstall Bun or use *-baseline build:
  https://github.com/oven-sh/bun/releases/download/bun-v1.3.4/bun-darwin-x64-baseline.zip

Root Cause

The ARM64 Claude binary's install subcommand installs the wrong architecture binary to ~/.local/bin/claude.

Workaround

Download and install the ARM binary directly:

# Download ARM binary directly from GCS
curl -fsSL -o ~/.local/bin/claude \
  https://storage.googleapis.com/claude-code-dist-86c565f3-f756-42ad-8dfa-d59b1c096819/claude-code-releases/2.0.67/darwin-arm64/claude

# Make executable
chmod +x ~/.local/bin/claude

# Verify it's ARM
file ~/.local/bin/claude
# Should show: Mach-O 64-bit executable arm64

Impact

• Apple Silicon users get x86_64 binary running under Rosetta
• Performance degradation from emulation
• Architecture conflicts with native npm dependencies (rollup, etc.)
• AVX warnings and potential instability
• Affects all users following official installation instructions on Apple Silicon

Additional Notes

The bootstrap script (https://claude.ai/install.sh) works correctly - the bug is specifically in the Claude Code binary's install subcommand.