hitting a strange pex issue deep in the depths of one of our ML tools, wondering if anyone’s encountered the same before:

pex: PEX is not zip safe, exploding to /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0
pex: Adding to the head of sys.path: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0
pex: Adding to the head of encodings.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/encodings
pex: Adding to the head of collections.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/collections
pex: Adding to the head of importlib.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/importlib
pex: Adding to the head of _pex.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/_pex
pex: Adding to the head of ctypes.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/ctypes
pex: Adding to the head of ctypes.macholib.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/ctypes/macholib
pex: Adding to the head of urllib.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/urllib
pex: Adding to the head of email.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/email
pex: Adding to the head of http.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/http
pex: Adding to the head of pkg_resources.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/pkg_resources
pex: Adding to the head of xml.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/xml
pex: Adding to the head of xml.parsers.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/xml/parsers
pex: Adding to the head of pkg_resources.extern.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/pkg_resources/extern
pex: Adding to the head of pkg_resources._vendor.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/pkg_resources/_vendor
pex: Adding to the head of pkg_resources._vendor.packaging.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/pkg_resources/extern/packaging
pex: Adding to the head of distutils.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/distutils
pex: Adding to the head of logging.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/logging
pex: Adding to the head of json.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/json
pex: Adding to the head of mpl_toolkits.__path__: /Users/kwilson/.pex/code/3abed9b0e11a4a550f42f3de7c47d7987a659cd0/mpl_toolkits
Traceback (most recent call last):
  File ".bootstrap/_pex/pex.py", line 364, in execute
  File ".bootstrap/_pex/pex.py", line 90, in _activate
  File ".bootstrap/_pex/environment.py", line 147, in activate
  File ".bootstrap/_pex/environment.py", line 198, in _activate
  File ".bootstrap/_pex/environment.py", line 64, in update_module_paths
AttributeError: '_NamespacePath' object has no attribute 'insert'