Cache directory validation rejects symlinks owned by other user

[wangvisual]

Version

0.8.1

Platform

Linux (x64)

Install channel

go install

Binary variant

standard

What happened, and what did you expect?

When the home directory's .cache symlink points to a shared filesystem location owned by another user, codebase-memory-mcp fails to verify cache directory permissions during startup. This occurs even though the user has full read/write access to the actual cache directory.

Error:

Failed to connect to MCP server "codebase-memory": codebase-memory-mcp: exact executable identity could not be verified (cache-private) - /path/to/cache: ancestry component validation failed (errno 17)

Reproduction

1. Setup:

   • User A has home directory /home/userA
   • Shared filesystem at /shared/fs owned by User B
   • User A's ~/.cache is symlinked to /shared/fs/userA/.cache
   • User A has rwx permissions on /shared/fs/userA/.cache and owns it

2. Command:

   export CBM_CACHE_DIR="$HOME/.cache/codebase-memory-mcp"
   codebase-memory-mcp --version

3. Expected:
   Should display version and proceed normally.

4. Actual:
   Error: ancestry component validation failed (errno 17)
   The binary refuses to use the cache directory because parent directories are owned by a different user.

Logs

codebase-memory-mcp: exact executable identity could not be verified (cache-private) - /shared/fs/userA/.cache/codebase-memory-mcp: ancestry component validation failed (errno 17)

Diagnostics trajectory (memory / performance / leak issues)

Project scale (if relevant)

No response

Confirmations

• I searched existing issues and this is not a duplicate.
• My reproduction uses shareable code (a dummy snippet or a public OSS repository), not proprietary code.