Fix PTY workdir and process group teardown

internal/pty/pty.go

@@ -6,6 +6,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"syscall"
 
 	cpty "github.com/creack/pty"
 )
@@ -19,11 +20,13 @@ type PTY struct {
 // Start spawns argv with stdin/stdout/stderr attached to a new PTY sized
 // (cols, rows). The returned PTY exposes the master fd for the parent to
 // read from and write to.
-func Start(argv []string, env []string, cols, rows uint16) (*PTY, error) {
+func Start(argv []string, env []string, workDir string, cols, rows uint16) (*PTY, error) {
 	if len(argv) == 0 {
 		return nil, fmt.Errorf("pty: empty argv")
 	}
 	cmd := exec.Command(argv[0], argv[1:]...)
+	cmd.Dir = workDir
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true, Setctty: true}
 	if env != nil {
 		cmd.Env = ensureTerm(env)
 	} else {
@@ -88,6 +91,10 @@ func (p *PTY) Close() error {
 		p.master = nil
 	}
 	if p.cmd != nil && p.cmd.Process != nil {
+		pid := p.cmd.Process.Pid
+		if pid > 0 {
+			_ = syscall.Kill(-pid, syscall.SIGKILL)
+		}
 		_ = p.cmd.Process.Kill()
 	}
 	return firstErr