$ make
lv2peg flute.ttl gen/Flute.peg
python portmeta.py
Traceback (most recent call last):
File "portmeta.py", line 62, in
cppFile = open("gen/FluteMeta.h", "w")
IOError: [Errno 2] No such file or directory: 'gen/FluteMeta.h'
make: *** [gen/FluteMeta.h] Error 1

Looks like a file that wasn't added to repo :)