Errors, documentation.

internal/zenutil/progress_unix.go

@@ -5,6 +5,7 @@ package zenutil
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"io"
 	"os"
 	"os/exec"
@@ -77,11 +78,14 @@ func (d *progressDialog) wait(extra *string, out *bytes.Buffer) {
 		case eerr.ExitCode() == -1 && atomic.LoadInt32(&d.closed) != 0:
 			err = nil
 		case eerr.ExitCode() == 1:
-			if extra != nil && *extra+"\n" == string(out.Bytes()) {
+			out := bytes.TrimSuffix(out.Bytes(), []byte{'\n'})
+			if extra != nil && *extra == string(out) {
 				err = ErrExtraButton
 			} else {
 				err = ErrCanceled
 			}
+		default:
+			err = fmt.Errorf("%w: %s", eerr, eerr.Stderr)
 		}
 	}
 	d.err = err

list_darwin.go

@@ -13,6 +13,9 @@ func list(text string, items []string, opts options) (string, error) {
 	if opts.extraButton != nil {
 		return "", fmt.Errorf("%w: extra button", ErrUnsupported)
 	}
+	if len(opts.defaultItems) > 1 {
+		return "", fmt.Errorf("%w: multiple default items", ErrUnsupported)
+	}
 
 	var data zenutil.List
 	data.Items = items

pwd.go

@@ -10,7 +10,7 @@ func Password(options ...Option) (usr string, pwd string, err error) {
 	return password(applyOptions(options))
 }
 
-// Username returns an Option to display the username (Unix only).
+// Username returns an Option to display the username.
 func Username() Option {
 	return funcOption(func(o *options) { o.username = true })
 }

util_unix.go

@@ -4,6 +4,7 @@ package zenity
 
 import (
 	"bytes"
+	"fmt"
 	"os/exec"
 	"strconv"
 	"strings"
@@ -66,11 +67,14 @@ func appendWindowIcon(args []string, opts options) []string {
 
 func strResult(opts options, out []byte, err error) (string, error) {
 	out = bytes.TrimSuffix(out, []byte{'\n'})
-	if err, ok := err.(*exec.ExitError); ok && err.ExitCode() == 1 {
-		if opts.extraButton != nil && *opts.extraButton == string(out) {
-			return "", ErrExtraButton
+	if eerr, ok := err.(*exec.ExitError); ok {
+		if eerr.ExitCode() == 1 {
+			if opts.extraButton != nil && *opts.extraButton == string(out) {
+				return "", ErrExtraButton
+			}
+			return "", ErrCanceled
 		}
-		return "", ErrCanceled
+		return "", fmt.Errorf("%w: %s", eerr, eerr.Stderr)
 	}
 	if err != nil {
 		return "", err