Problem: /plugin install superpowers fails — can't connect to github.com (app proxy doesn't cover git) —— Trove problem library

What you will run into

In Claude Code, /plugin install superpowers@claude-plugins-official or @superpowers-marketplace fails with fatal: unable to access 'https://github.com/obra/superpowers.git/': Failed to connect to github.com port 443 after 2045 ms.

Even with a global proxy configured in the app it doesn't connect — without TUN, the git subprocess doesn't go through the proxy.

Why this happens

Upstream Claude Code plugin marketplace install path = git clone of a GitHub repo (the marketplace site offers no zip download); direct connections to github.com:443 from CN are unstable/blocked;

app-level proxies don't cover git subprocesses (unless TUN/transparent proxy or explicit git proxy config).

The install flow is essentially "a CLI program invoking a git subprocess": on /plugin install, the CLI itself runs git clone, and the download is done not by the CLI's network stack but by the git subprocess it forks.

App-level proxies (the proxy toggle in the app's settings) only affect the app's own network stack (the HTTP client's proxy);

the git subprocess is an independent program with its own config (http.proxy in ~/.gitconfig) — unless the proxy is TUN/transparent mode (capturing all system traffic), git never knows a proxy exists and still connects directly.

That's the mechanism behind "proxy enabled but still failing".

The three countermeasures map to three layers: give git an explicit proxy (git config --global http.proxy ..., making the subprocess use the proxy); switch channels (the codeload tarball is directly reachable;

use curl to fetch the archive — curl runs in the CLI's own context, so the app-level proxy applies);

gh-proxy acceleration (domain-level replacement of the content). The diagnostic path is fixed: first see "which stage is stuck" (clone = git subprocess direct connection), then pick the matching layer's countermeasure.

Step by step

1. Probe first, then pick the route — Diagnose

curl -sI https://codeload.github.com/obra/superpowers/tar.gz/refs/tags/v6.3.0

If codeload is reachable, go the tarball route (1.7~1.9s in this environment).

2. Tarball direct install (measured PASS) — Required

curl -sL https://codeload.github.com/obra/superpowers/tar.gz/refs/tags/v6.3.0 | tar xz

Measured: codeload tarball 544K / 2.1s → install PASS.

3. Configure an explicit git proxy and retry — Required

git config --global http.proxy http://127.0.0.1:<port>

Or enable TUN/transparent proxy.

4. Accelerated channel — Required

gh-proxy-style acceleration (measured working 2026-08-28, 7.8s), or download the zip from a CN mirror and install offline; if all else fails, wire it in via the local-path method (see the symptom-6 entry).

How to confirm it works

Install flow completes (measured shape):

curl probe codeload → HTTP 200
tarball extracted with complete plugin dir structure → install PASS 

Other environments

Symptom

In Claude Code, /plugin install superpowers@claude-plugins-official or @superpowers-marketplace reports:

fatal: unable to access 'https://github.com/obra/superpowers.git/': Failed to connect to github.com port 443 after 2045 ms

A global proxy configured inside the app also does not work (without TUN, the git subprocess does not use the proxy).

Cause

The upstream Claude Code plugin marketplace install path = git clone of the GitHub repo (the marketplace site offers no zip download); domestic direct connection to github.com:443 is unstable/blocked; app-level proxy does not cover the git subprocess (unless TUN/transparent proxy or git is explicitly given a proxy).

Solution

1. Probe before choosing a path: curl -sI https://codeload.github.com/obra/superpowers/tar.gz/refs/tags/v6.3.0 — if codeload is reachable, install from the tarball directly (command in the "verified in this marketplace" section; 1.7~1.9s in this environment).
2. Give git an explicit proxy and retry: git config --global http.proxy http://127.0.0.1:<port>; or enable TUN/transparent proxy.
3. Use acceleration: gh-proxy-style acceleration (verified usable 2026-08-28, 7.8s), or download the zip from a domestic mirror and install offline (see Symptom 2).
4. Offline fallback: wire it in via the local-path method from Symptom 6.