Marketplace scanner drops root-repo plugins ({"source":"github","repo":"..."}) with no path

[BenMcGit]

Heads up — not 100% sure this is the right repo for it (the bug is in grok-build's
xai_grok_plugin_marketplace::scanner, and grok-build has issues/PRs disabled), but this
felt like the closest active tracker for marketplace/plugin compatibility. Redirect me if
there's a better place.

Bug

grok plugin marketplace add <claude-code-marketplace> silently drops any plugin entry
whose source is the plain {"source": "github", "repo": "org/repo"} shape (a root-of-repo
plugin, no subdirectory). Only the git-subdir shape (which has an explicit path) is
recognized.

This shape is valid per Claude Code's own marketplace schema — it's used by Anthropic's
canonical anthropics/claude-plugins-official marketplace — so any third-party Claude Code
marketplace with a root-repo plugin loses those entries with no warning to the user.

Repro

grok plugin marketplace add zapier/marketplace
grok plugin install sdk@zapier --trust
# Error: No marketplace plugin named "sdk" in "zapier".

zapier/marketplace's .claude-plugin/marketplace.json has sdk (and two others,
agent-skills and gtm-cheat-codes) defined as:

{
  "name": "sdk",
  "source": { "source": "github", "repo": "zapier/sdk" }
}

Running with --debug-file surfaces the actual cause, which never reaches stdout:

WARN xai_grok_plugin_marketplace::scanner: marketplace index entry 'sdk' has invalid source path: missing source path

Expected

Either:

• The scanner should support the github-source-type shape (no path required, clone repo
  root), matching Claude Code's own behavior, or
• If that shape is intentionally unsupported, the marketplace add command should surface a
  warning to the user instead of silently dropping the plugin (the WARN currently only
  appears with --debug-file).

Environment

• grok 0.2.106 (bde89716f679)
• macOS