Pass stderr from command to local terminal

CHANGELOG

@@ -1,3 +1,6 @@
+0.1.2:
+- Pass stderr from command to local terminal
+
 0.1.1:
 - Pass session environment variables to command
 

pkg/gate/portal.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
 	"os"
 	"os/exec"
 	"path"
@@ -59,18 +60,25 @@ func NewPortal(name string, address string, command []string) (*Portal, error) {
 			if len(command) > 1 {
 				args = command[1:]
 			}
-
 			cmd := exec.CommandContext(cmdCtx, command[0], args...)
+
 			cmd.Env = append(sshSession.Environ(), fmt.Sprintf("TERM=%s", ptyReq.Term))
 
+			stderr, err := cmd.StderrPipe()
+			if err != nil {
+				log.Printf("error: failed to create stderr pipe for portal %s: %s", name, err)
+				return
+			}
+			go func() {
+				io.Copy(sshSession.Stderr(), stderr)
+			}()
+
 			f, err := pty.Start(cmd)
 			if err != nil {
 				io.WriteString(sshSession, fmt.Sprintf("failed to start command: failed to initialize pseudo-terminal: %s\n", err))
 				sshSession.Exit(1)
 				return
 			}
-			defer f.Close()
-
 			go func() {
 				for win := range winCh {
 					setWinsize(f, win.Width, win.Height)
@@ -82,6 +90,7 @@ func NewPortal(name string, address string, command []string) (*Portal, error) {
 			}()
 			io.Copy(sshSession, f)
 
+			f.Close()
 			cmd.Wait()
 		},
 		PtyCallback: func(ctx ssh.Context, pty ssh.Pty) bool {