[...]
Interpreting music...
warning: type check for `stringTunings' failed; value `#<unspecified>'
must be of type `list'
This error comes from the missing definition for seven strings...
[8][16]
Preprocessing graphical objects...
Interpreting music...
Interpreting music...
Preprocessing graphical objects...
MIDI output to `bend-test.midi'...
Solving 1 page-breaking chunks...[1: 1 pages]
Drawing
systems.../home/fede/lilypond/usr/share/lilypond/current/ly/bend.ly:244:57:
In expression (parenthesize-tab-note-head grob):
/home/fede/lilypond/usr/share/lilypond/current/ly/bend.ly:244:57:
Unbound variable: parenthesize-tab-note-head
Sorry, this is a little bug in tablature.ly; please search the line
where you can find
#(define (parenthesize-tab-note-head grob)
and change it to
#(define-public (parenthesize-tab-note-head grob)
Then (hopefully) everything will be ok.