Frescobaldi/Mac question

[Tim McNamara]

Running convert-ly results in:

 Traceback (most recent call last):
  File 
"/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/py2app/apptemplate/lib/site.py",
 line 22, in <module>
    import os
zipimport.ZipImportError: can't decompress data; zlib not available



“locate zlib” finds multiple instances including slib.h, zlib.so, zlib.py, 
zlib.pyc, zlib.pyo, zlib.tcl, etc..  I’ve got zlib coming out of my ears.  
What’s being looked for that I don’t have?