Ok, now I'm getting a little further at least.

But is encounter a new error message, which I don’t understand:

import iotbx.pdb

  File "/Users/magnus/Downloads/cctbx_sources/iotbx/pdb/__init__.py", line 2, in <module>

    from cctbx.array_family import flex

  File "/Users/magnus/Downloads/cctbx_sources/cctbx/array_family/flex.py", line 2, in <module>

    import scitbx.array_family.flex

  File "/Users/magnus/Downloads/cctbx_sources/scitbx/array_family/flex.py", line 2, in <module>

    import boost.optional # import dependency

  File "/Users/magnus/Downloads/cctbx_sources/boost_adaptbx/boost/optional.py", line 2, in <module>

    import boost.python

  File "/Users/magnus/Downloads/cctbx_sources/boost_adaptbx/boost/python.py", line 129, in <module>

    floating_point_exceptions = floating_point_exceptions()

  File "/Users/magnus/Downloads/cctbx_sources/boost_adaptbx/boost/python.py", line 122, in floating_point_exceptions

    import libtbx.load_env

  File "/Users/magnus/Downloads/cctbx_sources/libtbx/load_env.py", line 5, in <module>

    libtbx.env = libtbx.env_config.unpickle()

  File "/Users/magnus/Downloads/cctbx_sources/libtbx/env_config.py", line 2194, in unpickle

    set_preferred_sys_prefix_and_sys_executable(build_path=build_path)

  File "/Users/magnus/Downloads/cctbx_sources/libtbx/env_config.py", line 2110, in set_preferred_sys_prefix_and_sys_executable

    if (op.samefile(build_path, dirname)):

  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.py", line 162, in samefile

    s1 = os.stat(f1)

OSError: [Errno 2] No such file or directory: ''