Problem: skillspector mcp hangs with no output (missing optional deps) —— Trove problem library

What you will run into

Using MCP server mode (skillspector mcp), the process hangs with no output, like a freeze — no error, no log. You think the tool is broken; it's actually that the optional components MCP mode depends on aren't fully installed (Issue #199 scenario).

Why this happens

MCP mode depends on optional components; the default pip install skillspector doesn't install everything; when components are missing, stdio session protocol initialization stalls, and a hang gives no error at all.

The main scan path skillspector scan completes scans without MCP.

MCP stdio mode is essentially "a child process + stdin/stdout" JSON-RPC: the MCP client launches skillspector mcp as a subprocess and both sides exchange JSON messages line by line; the protocol's first step is an initialize handshake (request -> response).

When optional deps are missing, the subprocess fails at import time — before the protocol has started.

No request exists, so nothing can produce an error message; the client just waits forever, which is exactly the hang you see.

"No error" is therefore the key clue: hang + total silence almost always means the process never started (missing deps / import failure), not an infinite loop.

The diagnostic order is fixed by this: --help first (if it prints, the package itself loads fine, so the problem is on the protocol side) -> install the optional deps; while troubleshooting, keep using the scan main path to get work done without MCP.

Step by step

1. Ctrl+C out of the hang — Required

If it hangs with no output, exit first; don't wait around.

2. Confirm the CLI layer works — Required

skillspector mcp --help

Normal output = CLI layer fine; the problem is on the MCP session-protocol side (missing optional deps).

3. Install the MCP-related optional deps — Advanced

Install per project docs, then restart MCP mode (names per docs; example skillspector[mcp]).

4. Use the main path while troubleshooting — Required

skillspector scan <target dir>

Scans complete without MCP (measured detection of a constructed sample in this marketplace).

How to confirm it works

MCP mode no longer hangs (expected shape):

skillspector mcp
→ starts normally, stdout shows MCP protocol handshake/ready output

Or confirm the main path works: skillspector scan outputs scan results normally.

Other environments

Symptom

The process hangs with no output when using MCP server mode (skillspector mcp).

Cause

MCP mode depends on optional components that a default pip install does not include (Issue #199 scenario); stdio hangs silently, looking like a freeze.

Solution

1. First Ctrl+C to exit, then confirm dependencies: install the MCP-related optional dependencies per the project docs and restart.
2. While troubleshooting use the skillspector scan main path (scanning works without MCP).
3. When hung, check whether skillspector mcp --help outputs normally (if it does, the CLI layer is fine and the issue is in the session protocol side).