This question deals with barre chord notation for guitar using the
TextSpanner command in Lilypond. This approach is also described in the Lilypond documentation. However, this approach only works if the barre is held for more than one note value:
(picture from the Lilypond documentation)
It does not work if you only need to barre for a single note value, such as indicated (via a different convention) here:
TextSpanner method for a single note value results in "warning: unterminated text spanner", and the barre command is ignored, so no barre indication is displayed.
I would like to indicate a barre over a single note value just like in the first example above, with a short horizontal line. Is there a way to modify the method used in the above quoted answer in such a way that this is possible? If not, how could one generate a barre indication for a single note value such as given in the second example above (or in any other reasonably looking way)?