conda skeleton build fails

[henningpeters]

Building conda packages via conda skeleton pypi preshed fails with following error:

Traceback (most recent call last):
  File "setup.py", line 107, in <module>
    main(MOD_NAMES, use_cython)
  File "setup.py", line 100, in main
    run_setup(exts)
  File "setup.py", line 88, in run_setup
    import headers_workaround
ImportError: No module named 'headers_workaround'