'make website' ends successfully, without errors being printed, by
using 'pt' as my language name.
'make doc', however, fails and what seems to cause is that
"scripts/lilypond-book.py" is not finding the library 'lilylib' for
importing. See the following command-lines extracted from the output
of 'make doc'
$ cd input/regression
$ LILYPOND_VERSION=2.19.81
Traceback (most recent call last):
File "../../scripts/lilypond-book.py", line 62, in <module>
import lilylib as ly
ImportError: No module named lilylib
python/lilylib.py exists, but I don't know why 'make doc' failed to
find it. Maybe that's something to throw to bug-lilypond list?