fix(bash): kill process group immediately on cancel

Watches for context cancellation in a goroutine and kills the entire process group plus closes the pipe immediately, instead of waiting for cmd.Wait() which deadlocks when child processes hold the pipe open.

commit: ba3f3287e9514f73c67c6658142964751c90efc1
author: patriceckhart · 6mo ago · 2026-04-23 16:47 UTC
parent: daaa062
signature: unsigned

1 file · +14 -5

M internal/agent/tools/bash.go +14 -5


@@ -82,6 +82,20 @@ func (t *BashTool) Execute(ctx context.Context, raw json.RawMessage, progress fu
82	82		// Writer to both the buffer (trimmed) and progress callback.
83	83		captured := &bytes.Buffer{}
84	84		done := make(chan struct{})
	85	+
	86	+	// Watch for context cancellation and kill the entire process
	87	+	// group immediately. exec.CommandContext only kills the direct
	88	+	// process, but child processes (e.g. grep spawned by the shell)
	89	+	// keep the output pipe open and block cmd.Wait() indefinitely.
	90	+	go func() {
	91	+	select {
	92	+	case <-runCtx.Done():
	93	+	killProcessGroup(cmd)
	94	+	// Close the write end so the reader goroutine unblocks.
	95	+	pw.Close()
	96	+	case <-done:
	97	+	}
	98	+	}()
85	99		go func() {
86	100		defer close(done)
87	101		buf := make([]byte, 4096)

@@ -111,11 +125,6 @@ func (t *BashTool) Execute(ctx context.Context, raw json.RawMessage, progress fu
111	125		pw.Close()
112	126		<-done
113	127
114		-	// On hard cancel, try to kill the process group.
115		-	if ctx.Err() != nil && cmd.Process != nil {
116		-	killProcessGroup(cmd)
117		-	}
118		-
119	128		output := captured.String()
120	129		truncBytes := captured.Len() >= maxBashBytes
121	130		lines := strings.Split(output, "\n")

 	// Writer to both the buffer (trimmed) and progress callback.
 	captured := &bytes.Buffer{}
 	done := make(chan struct{})
+	// Watch for context cancellation and kill the entire process
+	// group immediately. exec.CommandContext only kills the direct
+	// process, but child processes (e.g. grep spawned by the shell)
+	// keep the output pipe open and block cmd.Wait() indefinitely.
+	go func() {
+		select {
+		case <-runCtx.Done():
+			killProcessGroup(cmd)
+			// Close the write end so the reader goroutine unblocks.
+			pw.Close()
+		case <-done:
+		}
+	}()
 	go func() {
 		defer close(done)
 		buf := make([]byte, 4096)
 	pw.Close()
 	<-done
-	// On hard cancel, try to kill the process group.
-	if ctx.Err() != nil && cmd.Process != nil {
-		killProcessGroup(cmd)
-	}
 	output := captured.String()
 	truncBytes := captured.Len() >= maxBashBytes
 	lines := strings.Split(output, "\n")