Comment 2 for bug 387536

Any text with an ampersand will trigger the bug.

$ zenity --info --text 'This has an & in it'

The following is printed to stderr:
(zenity:21569): Gtk-WARNING **: Failed to set text from markup due to error parsing markup: Error on line 1: Character ' ' is not valid at the start of an entity name; the & character begins an entity; if this ampersand isn't supposed to be an entity, escape it as &

And zenity displays its default "All updates are complete" dialog instead of the text.

Ideally, it should be told to ignore Pango markup. Failing that, the man page should explicitly inform users that they need to escape anything that could be interpreted as Pango markup.