I just build a jupyter-labs pex by making a requirements file from

pip freeze

then using that as the input to

pex -r /tmp/jupyterlab-requirements.txt -o jupyter-labs.pex -p /Users/myacct/.pyenv/shims/python

. When I go to run the pex with

jupyter-labs.pex -e jupyterlab.labapp:main

I get the following error:

jupyter-labs.pex -e jupyterlab.labapp:main
Traceback (most recent call last):
  File "/Users/myacct/.pyenv/versions/3.6.9/lib/python3.6/runpy.py", line 185, in _run_module_as_main
    mod_name, mod_spec, code = _get_main_module_details(_Error)
  File "/Users/myacct/.pyenv/versions/3.6.9/lib/python3.6/runpy.py", line 219, in _get_main_module_details
    return _get_module_details(main_name)
  File "/Users/myacct/.pyenv/versions/3.6.9/lib/python3.6/runpy.py", line 128, in _get_module_details
    spec = importlib.util.find_spec(mod_name)
  File "/Users/myacct/.pyenv/versions/3.6.9/lib/python3.6/importlib/util.py", line 91, in find_spec
    return _find_spec(fullname, None)
  File "<frozen importlib._bootstrap>", line 894, in _find_spec
  File "<frozen importlib._bootstrap_external>", line 1157, in find_spec
  File "<frozen importlib._bootstrap_external>", line 1131, in _get_spec
  File "<frozen importlib._bootstrap_external>", line 1112, in _legacy_get_spec
  File "<frozen importlib._bootstrap>", line 441, in spec_from_loader
  File "<frozen importlib._bootstrap_external>", line 544, in spec_from_file_location
  File "/Users/myacct/dev/virtualenvs/tmp-bc02eb6e921a2fd/jupyter-labs.pex/__main__.py", line 3
    [ -n "$PYENV_DEBUG" ] && set -x
                      ^
SyntaxError: invalid syntax

the code in question is shell code which Python is rejecting

This is the

__main__.py

in the built pex.

right, but the first part of that script is a bash script, not a Python script. the Python interpreter will not parse bash.

Looks like it is something with the jupyter-lab setup. I just redid it with a

sphinx

example and the

__main__.py

contains nothing but python in that pex.

interesting, so the interaction of pex and jupyter-lab is doing something weird then

I think I may of found the problem.

we potentially could have pex try to detect this case by flagging files passed to

-p

that have a shebang line that is not python

Is this something

pex

should error out on? If yes, I'll make an issue.

it is worth reporting. it may not be perfectly solvable but worth giving some thought to

I'll make an issue. At the worse it gets closed and we have a more permanent memory in github than this free slack.

-p

!=

--python

Yup. User error. 👁️ 👁️