deactivate command not available in shell scripts or sub-shells (activate script does not export "deactivate")

[geopanther]

Issue

When activating an venv environment, the command "deactivate" is only available in the current instance of the shell and not in a shellscript (a shellscript is always executed in sub-shell (separate instance)) or any subshel

Environment

Provide at least:

• OS: macOS Big Sur 11.7.10 (20G1427)
• Using bash version "3.2.57(1)-release" from Homebrew
• pip list of the host python where virtualenv is installed:

$ pip list
Package    Version
---------- -------
pip        23.2.1
setuptools 56.0.0

Output of the virtual environment creation

Make sure to run the creation with -vvv --with-traceback:

$ python3 --with-traceback -vvv -m venv .venv_py3.11
unknown option --with-traceback
usage: /Library/Frameworks/Python.framework/Versions/3.11/Resources/Python.app/Contents/MacOS/Python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Try `python -h' for more information.

$ python3 -vvv -m venv .venv_py3.11

-> see attached console-output.txt

Steps to reproduce:

$ source .venv_py3.11/bin/activate
$ bash
$ deactivate
bash: deactivate: command not found
$ exit
exit
$ deactivate
$

Suggested solution:
Add export -f deactivate to <virtual_env_dir>/bin/activate

[gaborbernat]

That will still keep the activation in the first shell as it's not possible to change parent shell envs, so this would cause more confusion than benefit.