gps: Set pgroup controls in cmd constructor

Author: sdboyer

internal/gps/cmd_unix.go

@@ -35,6 +35,17 @@ func commandContext(ctx context.Context, name string, arg ...string) cmd {
 		cancel: cancel,
 		ctx:    ctx,
 	}
+
+	// Force subprocesses into their own process group, rather than being in the
+	// same process group as the dep process. Because Ctrl-C sent from a
+	// terminal will send the signal to the entire currently running process
+	// group, this allows us to directly manage the issuance of signals to
+	// subprocesses.
+	c.Cmd.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+		Pgid:    0,
+	}
+
 	return c
 }
 
@@ -53,16 +64,6 @@ func (c cmd) CombinedOutput() ([]byte, error) {
 	c.Cmd.Stdout = &b
 	c.Cmd.Stderr = &b
 
-	// Force subprocesses into their own process group, rather than being in the
-	// same process group as the dep process. Ctrl-C sent from a terminal will
-	// send the signal to the entire running process group, so This allows us to
-	// directly manage the issuance of signals to subprocesses in that common
-	// case.
-	c.Cmd.SysProcAttr = &syscall.SysProcAttr{
-		Setpgid: true,
-		Pgid:    0,
-	}
-
 	if err := c.Cmd.Start(); err != nil {
 		return nil, err
 	}