关于 codex-home 磁盘占用的疑问

[Robbot-Q]

大家好，我发现Multica似乎会依据 issue+agent的维度 创建独有的codex_home,但是里面好像把codex的插件(skill)都完整的复制了一遍，每一次都会有100m大小，这个大小和这个机制是正常的吗？

[ADanMan]

This was a real bug, not expected behavior, and it's already fixed on main (not yet in the code you're looking at if you're on a build before that fix).

Root cause: seedUserCodexSkills in server/internal/daemon/execenv/codex_user_skills.go used to do a full recursive copy (copyDirTree/copyFile) of every directory under your shared ~/.codex/skills/ into each task's per-task CODEX_HOME/skills/. For a user with npm-backed skills that's ~100MB, and it was re-copied from scratch on every task start — hydrateCodexSkills wipes and re-seeds skills/ on both the Prepare and the Reuse path (server/internal/daemon/execenv/execenv.go:686-699). Worse, it was never reclaimed while the issue stayed open: the GC artifact sweep only matches node_modules/.next/.turbo, and whole-directory reclaim needs the issue to reach a terminal state first. So disk cost scaled with the number of live task directories, exactly matching what your screenshots show.

Fix: PR #6742 (MUL-6000, "link user Codex skills into codex-home instead of copying them"), merged 2026-08-11, first shipped in tag v0.4.23. It replaces the copy with a directory link (symlink on Unix, junction on Windows) — the same approach already used for the other two shared resources in that per-task home, sessions (linkCodexSessionsToStore) and the plugin cache (exposeSharedCodexPluginCache). A skill directory is read-only input to the CLI, so there was never a real reason to isolate it via copy. The PR also fixed a related GC bug: on Windows, createDirLink falls back to a directory junction, and the GC's sweep/size-accounting previously only checked for os.ModeSymlink, so it would have walked into and deleted content inside the linked target — that's now guarded too.

If you're seeing this on a recent build, please confirm your Multica version (multica --version or check the app's About screen); if it's below v0.4.23, upgrading should resolve it. If you're already on v0.4.23+ and still seeing full-size copies rather than links under codex-home/skills/, that would be a regression worth a fresh, separate report with your version and OS.