make test fails → texi2html (?) error

[Malte Meyn]

Hi list,

I tried to compile the regression tests (make test) but this failed with 
the following message in input/regression/collated-files.texilog.log:

Undefined subroutine &main::get_index called at 
/home/malte/lilypond/Documentation/lilypond-texi2html.init line 2408.

What’s this? I found the same message in the list archive 
(https://lists.gnu.org/archive/html/lilypond-devel/2015-03/msg00084.html) 
but I couldn’t find any other hints what to do now. If that helps, my 
texi2html version is 5.0.

Cheers,
Malte