Plugin marketplace: /plugin & /reload-plugins wipe marketplace dir and fail to re-clone (owner-prefixed path mismatch with CLI) → all plugins + MCP servers fail to load

Summary

The in-app plugin loader (/plugin, /reload-plugins, and startup) and the CLI (claude plugin marketplace …) disagree on the marketplace install path. The in-app loader empties the marketplace directory and then fails to re-clone, leaving 0 plugins · 21 errors and taking down every plugin — including plugin-provided MCP servers (e.g. sentry, supabase, posthog). The CLI can repopulate it, but the very next /plugin or /reload-plugins wipes it again, so there is no way to recover from the UI.

Environment

• Claude Code 2.1.195
• macOS (darwin 25.5.0)
• Marketplace: claude-plugins-official (anthropics/claude-plugins-official), 21 plugins installed

What happens

known_marketplaces.json records:

"installLocation": "/Users/<me>/.claude/plugins/marketplaces/claude-plugins-official"

i.e. the CLI installs to marketplaces/<repo> = claude-plugins-official.

But the in-app loader tries to clone to the owner-prefixed path marketplaces/anthropics-claude-plugins-official, and fails:

Failed to load all marketplaces. Errors: claude-plugins-official: Failed to load marketplace
"claude-plugins-official" from source (github): Failed to clone marketplace repository:
Cloning into '/Users/<me>/.claude/plugins/marketplaces/anthropics-claude-plugins-official'...
fatal: Invalid path '/Users/<me>/.claude/plugins/marketplaces/anthropics-claude-plugins-official': No such file or directory

/reload-plugins then reports:

Reloaded: 0 plugins · 0 skills · 25 agents · 0 hooks · 0 plugin MCP servers · 0 plugin LSP servers
21 errors during load. Run /doctor for details.

and /doctor lists all 21 plugins as Marketplace claude-plugins-official failed to load: cache-miss.

Most importantly: after each /plugin or /reload-plugins, ~/.claude/plugins/marketplaces/claude-plugins-official/ is left empty (the loader appears to clear the directory before the clone, and the clone fails, so nothing is restored).

Workaround (partial)

From a shell:

claude plugin marketplace update claude-plugins-official

re-clones successfully into marketplaces/claude-plugins-official and claude plugin list shows all plugins enabled. But the next time /plugin or /reload-plugins runs (including, presumably, at the next session start), the in-app loader empties the dir again and the plugins/MCP servers disappear. Adding a symlink anthropics-claude-plugins-official -> claude-plugins-official did not help — the loader still wiped the real dir.

The plugin caches under ~/.claude/plugins/cache/claude-plugins-official/<plugin>/<version>/ remain intact throughout; only the marketplaces/ checkout is destroyed.

Steps to reproduce

1. Have claude-plugins-official installed via CLI (populates marketplaces/claude-plugins-official).
2. Run /reload-plugins (or open /plugin).
3. Observe 0 plugins · 21 errors, and that marketplaces/claude-plugins-official/ is now empty.
4. Run claude plugin marketplace update claude-plugins-official — repopulates, CLI sees plugins again.
5. Run /reload-plugins again — wiped again. Loop.

Suggested fixes

1. Reconcile the two path conventions. The in-app loader should read installLocation from known_marketplaces.json rather than deriving an <owner>-<repo> path that the CLI never writes.
2. Never destroy the existing checkout before a successful clone/pull. Clone to a temp dir and swap on success, so a failed clone can't leave the marketplace empty and brick every plugin.
3. Investigate the fatal: Invalid path … No such file or directory clone failure (looks like the parent path/target isn't created before git clone).