[BUG] Orphaned plugin marketplace git clone busy-loops at ~80% CPU for days after the session exits (Linux)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

A background git clone of the official plugin marketplace was left orphaned (its parent became systemd --user) after the Claude Code session that started it exited. It busy-looped at ~80% CPU for 3 days, keeping one CPU core at 100°C and the laptop fan near max the whole time. SIGTERM was ignored; it needed kill -9.

• Started Sep 15 14:05, still running on Sep 18.
• Its git index-pack --stdin child was idle in pipe_read while the parent git spun in state R.
• The clone target folder anthropics-claude-plugins-official doesn't exist. The marketplace is actually installed at ~/.claude/plugins/marketplaces/claude-plugins-official (per known_marketplaces.json) and had updated normally, so this clone was a leftover.

What Should Happen?

Marketplace git operations should have a timeout, and background git processes should be killed when the session that started them exits instead of running forever.

Error Messages/Logs

PID      %CPU  ELAPSED     STARTED                   STAT
3972130  78.8  3-01:02:49  Tue Sep 15 14:05:30 2026  Rl   (parent PID: systemd --user)

/usr/bin/git -c core.fsmonitor= -c core.hooksPath=/dev/null -c core.askPass= -c submodule.recurse=false -c log.showSignature=false -c gc.auto=0 -c maintenance.auto=false -c core.sshCommand=ssh -o BatchMode=yes -o StrictHostKeyChecking=yes -c protocol.ext.allow=never -c protocol.fd.allow=never -c protocol.git.allow=never -c protocol.ftp.allow=never -c protocol.ftps.allow=never clone --depth 1 --recurse-submodules --shallow-submodules -- git@github.com:anthropics/claude-plugins-official.git ~/.claude/plugins/marketplaces/anthropics-claude-plugins-official

child: /usr/lib/git-core/git --shallow-file .../anthropics-claude-plugins-official/.git/shallow.lock index-pack --stdin --fix-thin --keep=fetch-pack  (State: S, wchan: pipe_read, 0% CPU)

Steps to Reproduce

I couldn't reproduce it on purpose. What I observed:

1. Use Claude Code normally on Linux with the official plugin marketplace installed (several sessions open over a few days).
2. At some point a background marketplace git clone (over SSH) starts, and the session that launched it exits.
3. The orphaned git clone keeps running at ~80% CPU indefinitely (3+ days in my case) until killed with kill -9.

Check with: ps -eo pid,etime,pcpu,args | grep "[g]it .clone.claude-plugins-official"

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.276 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

Ubuntu 24.04, kernel 6.8, Intel Core Ultra 5 135H (Dell Precision 3591). I noticed it only because the fan never stopped for days; CPU temp dropped from 101°C to 66°C within 2 minutes of killing the process.