Making lazy-extractors fails

[royale1223]

I was trying to compile with lazy-extractors enabled and got the following error:

$ make lazy-extractors 
/usr/bin/env python devscripts/make_lazy_extractors.py youtube_dl/extractor/lazy_extractors.py
WARNING: Lazy loading extractors is an experimental feature that may not always work
Traceback (most recent call last):
  File "devscripts/make_lazy_extractors.py", line 89, in <module>
    src = build_lazy_ie(ie, name)
  File "devscripts/make_lazy_extractors.py", line 57, in build_lazy_ie
    s += '\n' + getsource(ie.suitable)
  File "/usr/lib/python2.7/inspect.py", line 700, in getsource
    lines, lnum = getsourcelines(object)
  File "/usr/lib/python2.7/inspect.py", line 689, in getsourcelines
    lines, lnum = findsource(object)
  File "/usr/lib/python2.7/inspect.py", line 528, in findsource
    raise IOError('source code not available')
IOError: source code not available
Makefile:111: recipe for target 'youtube_dl/extractor/lazy_extractors.py' failed
make: *** [youtube_dl/extractor/lazy_extractors.py] Error 1