Environment variable from .env available in `pipenv run python` but not in `pipenv shell`

I’ve run into a strange error where a environment variable declared in a .env file is available in pipenv run python but not in pipenv shell. This only happens if the variable is named DYLD_LIBRARY_PATH.

I’m using macOs High Sierra, Python 3.6.3, pipenv 8.2.6.

Setup to reproduce:

$ mkdir envtest
$ cd envtest
$ pipenv --three
Creating a virtualenv for this project…
Using /usr/local/bin/python3.6m to create virtualenv…
⠋Running virtualenv with interpreter /usr/local/bin/python3.6m
Using base prefix '/usr/local/Cellar/python3/3.6.3/Frameworks/Python.framework/Versions/3.6'
New python executable in /Users/tf/.local/share/virtualenvs/envtest-S14rkyS9/bin/python3.6
Also creating executable in /Users/tf/.local/share/virtualenvs/envtest-S14rkyS9/bin/python
Installing setuptools, pip, wheel...done.

Virtualenv location: /Users/tf/.local/share/virtualenvs/envtest-S14rkyS9
Creating a Pipfile for this project…
$ echo "DYLD_LIBRARY_PATH=Teststring" > .env
$ cat .env
DYLD_LIBRARY_PATH=Teststring

Now this works as expected:

$ pipenv run python
>>> import os; os.environ['DYLD_LIBRARY_PATH']
'Teststring'

And this does not:

$ pipenv shell
Loading .env environment variables…
Spawning environment shell (/bin/zsh). Use 'exit' to leave.
source /Users/tf/.local/share/virtualenvs/envtest-S14rkyS9/bin/activate
$ echo $DYLD_LIBRARY_PATH

$ python
>>> import os; os.environ['DYLD_LIBRARY_PATH']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/tf/.local/share/virtualenvs/envtest-S14rkyS9/bin/../lib/python3.6/os.py", line 669, in __getitem__
    raise KeyError(key) from None
KeyError: 'DYLD_LIBRARY_PATH'

[tfeldmann]

It only affects the DYLD_LIBRARY_PATH variable.

To test I added three more variables to the .env file to check whether it has something to do with the underscores:

SOMETHING=something
SOMETHING_1=something1
SOMETHING_1_2=something2

They are fully available in $ pipenv run python and $ pipenv shell. DYLD_LIBRARY_PATH is only available in $ pipenv run python.

The variable is often needed for PySide installations.

[straz]

I have experienced this same problem. I suspect MacOS is treating DYLD_LIBRARY_PATH specially.

This seems like a likely explanation:

It turns out that this is due to a new ‘feature’ in System Integrity Protection. It will delete DYLD_* variables when launching subprocesses.

Have you tried to reproduce this on your own system with DYLD_LIBRARY_PATH? I can reproduce this on a fairly new MacOS laptop (cleanly installed Mac OS 10.14.6 with no profile or rc files.)