The 85-Byte `nul` File That Broke an Entire Codebase Index
How indexing C:\codes\zhimalab with codebase-memory-mcp failed: a catch-all error swallowed the real cause, two red herrings (a broken cache tree and C:\tmp's DACL) led me astray, and a clean clone + file bisection finally pinned it to an 85-byte stray file named nul — a Windows reserved device name.