fun with wait groups; prevents hanging

vendor/github.com/packer-community/winrmcp/winrmcp/cp.go

@@ -176,13 +176,30 @@ func cleanupContent(client *winrm.Client, filePath string) error {
 	}
 
 	defer shell.Close()
-	cmd, err := shell.Execute("powershell", "Remove-Item", filePath, "-ErrorAction SilentlyContinue")
+	script := fmt.Sprintf(`Remove-Item %s -ErrorAction SilentlyContinue`, filePath)
+
+	cmd, err := shell.Execute(winrm.Powershell(script))
 	if err != nil {
 		return err
 	}
+	defer cmd.Close()
+
+	var wg sync.WaitGroup
+	copyFunc := func(w io.Writer, r io.Reader) {
+		defer wg.Done()
+		io.Copy(w, r)
+	}
+
+	wg.Add(2)
+	go copyFunc(os.Stdout, cmd.Stdout)
+	go copyFunc(os.Stderr, cmd.Stderr)
 
 	cmd.Wait()
-	cmd.Close()
+	wg.Wait()
+
+	if cmd.ExitCode() != 0 {
+		return fmt.Errorf("cleanup operation returned code=%d", cmd.ExitCode())
+	}
 	return nil
 }
 

vendor/vendor.json

@@ -959,10 +959,10 @@
 			"revision": "179d4d0c4d8d407a32af483c2354df1d2c91e6c3"
 		},
 		{
-			"checksumSHA1": "iApv8tX8vuAvzyY6VkOvW+IzJF8=",
+			"checksumSHA1": "XXmfaQ8fEupEgaGd6PptrLnrE54=",
 			"path": "github.com/packer-community/winrmcp/winrmcp",
-			"revision": "078cc0a785c9da54158c0775f06f505fc1e867f8",
-			"revisionTime": "2017-06-07T14:21:56Z"
+			"revision": "e1b7d6e6b1b1a27984270784190f1d06ad91888b",
+			"revisionTime": "2017-09-29T21:51:32Z"
 		},
 		{
 			"checksumSHA1": "oaXvjFg802gS/wx1bx2gAQwa7XQ=",