From c639a848c2953d92b1f111c124be0ddd007f4d83 Mon Sep 17 00:00:00 2001
From: Snider <snider@host.uk.com>
Date: Tue, 17 Mar 2026 05:56:22 +0000
Subject: [PATCH] fix: PID polling fallback for process completion detection
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proc.Wait() hangs when Claude Code's child processes inherit pipes.
Added PID polling every 5s — when the main process is dead (Signal(0)
fails), force completion even if pipes are still open.

Fixes: empty agent logs, missing completion events, stuck queue drain.

Co-Authored-By: Virgil <virgil@lethean.io>
---
 pkg/agentic/dispatch.go | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/pkg/agentic/dispatch.go b/pkg/agentic/dispatch.go
index 85e3e33..b54429a 100644
--- a/pkg/agentic/dispatch.go
+++ b/pkg/agentic/dispatch.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"syscall"
 	"time"
 
 	coreio "forge.lthn.ai/core/go-io"
@@ -115,7 +116,34 @@ func (s *PrepSubsystem) spawnAgent(agent, prompt, wsDir, srcDir string) (int, st
 	pid := proc.Info().PID
 
 	go func() {
-		proc.Wait()
+		// Wait for process exit with PID polling fallback.
+		// go-process Wait() can hang if child processes inherit pipes.
+		// Poll the PID every 5s — if the process is gone, force completion.
+		done := make(chan struct{})
+		go func() {
+			proc.Wait()
+			close(done)
+		}()
+
+		ticker := time.NewTicker(5 * time.Second)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-done:
+				goto completed
+			case <-ticker.C:
+				// Check if main process is still alive
+				p, err := os.FindProcess(pid)
+				if err != nil {
+					goto completed
+				}
+				if err := p.Signal(syscall.Signal(0)); err != nil {
+					// Process is dead — force cleanup
+					goto completed
+				}
+			}
+		}
+	completed:
 
 		// Write captured output to log file
 		if output := proc.Output(); output != "" {