xclip verbose error output.

internal/desktop/clipboard.go

@@ -1,17 +1,40 @@
 package desktop
 
 import (
+	"fmt"
+	"bytes"
 	"os/exec"
 	"strings"
 )
 
 func (manager *DesktopManagerCtx) ReadClipboard() (string, error) {
-	out, err := exec.Command("xclip", "-selection", "clipboard", "-o").Output()
-	return string(out), err
+	cmd := exec.Command("xclip", "-selection", "clipboard", "-o")
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	if err != nil {
+		msg := strings.TrimSpace(string(stderr.Bytes()))
+		return "", fmt.Errorf("%s", msg)
+	}
+
+	return string(stdout.Bytes()), nil
 }
 
 func (manager *DesktopManagerCtx) WriteClipboard(data string) error {
 	cmd := exec.Command("xclip", "-selection", "clipboard", "-i")
-    cmd.Stdin = strings.NewReader(data)
-	return cmd.Run()
+	cmd.Stdin = strings.NewReader(data)
+
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	if err != nil {
+		msg := strings.TrimSpace(string(stderr.Bytes()))
+		return fmt.Errorf("%s", msg)
+	}
+
+	return nil
 }