merge_cache used a flat listdir() against a nested cache
(<compiler>/<arch-abi>/cg<N>_<hash>/) so it matched nothing — the vault's
DLL mirror has been empty since the tool shipped. Walk the tree and keep
relative paths: the same content-keyed filename exists under different cg
dirs with different compiled bytes, so flattening would mix emitter
generations. stats() walks recursively to match.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Overlay coverage (overlay_captures.json + the gcc-compiled cache DLLs) normally
lives only in gitignored build dirs, so a `cmake` clean or fresh worktree wipes
it (re-derivable only by replaying those areas). coverage_vault.py maintains one
additive vault OUTSIDE any build dir: `merge` unions captures by variant
(load_addr + bytes hash; same variant unions executed/entry PCs, distinct
variants all kept) and copies content-keyed cache DLLs (copy-if-absent/newer).
Wired into Tomba's overlay_autocompile_cmd so every compile backs up additively;
also runnable by hand to consolidate scattered build dirs. The vault holds
game-derived bytes, so it stays private/gitignored (this script does not).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Matthew Stanley