Double parenthesis in activated venv generated by Python 3.12.10

[IterableTrucks]

Bug report

Bug description:

python3.12 -m venv venv
source venv/bin/activate

There will be double parenthesis displayed on the terminal. This bug may be related to this commit because Python 3.12.9 is normal.

CPython versions tested on:

3.12

Operating systems tested on:

Linux

[hugovk]

Please could you paste the terminal output?

This is what I get on macOS using iTerm:

/private/tmp via  v3.1.3
❯ python3.12 -m venv venv
source venv/bin/activate

/private/tmp via  v3.12.10 (venv) via  v3.1.3 took 10s
❯ python3.12 --version
Python 3.12.10

/private/tmp via  v3.12.10 (venv) via  v3.1.3

[i9wa4]

I encountered this too.

[srv1] [2025-04-10 22:27:08] zsh [~]
$ lsb_release -d
No LSB modules are available.
Description:    Ubuntu 24.04.2 LTS
[srv1] [2025-04-10 22:27:26] zsh [~]
$ pyenv global 3.12.10
[srv1] [2025-04-10 22:27:27] zsh [~]
$ which python
/home/i9wa4/.pyenv/shims/python
[srv1] [2025-04-10 22:27:35] zsh [~]
$ python --version
Python 3.12.10
[srv1] [2025-04-10 22:27:58] zsh [~]
$ python -m venv venv3.12.10
[srv1] [2025-04-10 22:28:11] zsh [~]
$ source venv3.12.10/bin/activate
((venv3.12.10) ) [srv1] [2025-04-10 22:28:11] zsh [~]
$ 

[brianschubert]

I can reproduce this. I think this may be related to this diff, which was included in the 3.12 backport, but not in the main PR

 if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT:-}" ] ; then
     _OLD_VIRTUAL_PS1="${PS1:-}"
-    PS1=__VENV_PROMPT__"${PS1:-}"
+    PS1="("__VENV_PROMPT__") ${PS1:-}"
     export PS1
-    VIRTUAL_ENV_PROMPT=__VENV_PROMPT__
-    export VIRTUAL_ENV_PROMPT
 fi

For context, the generated activate script looks like this:

# [...]
VIRTUAL_ENV_PROMPT='(venv) '
export VIRTUAL_ENV_PROMPT

# unset PYTHONHOME if set
# this will fail if PYTHONHOME is set to the empty string (which is bad anyway)
# could use `if (set -u; : $PYTHONHOME) ;` in bash
if [ -n "${PYTHONHOME:-}" ] ; then
    _OLD_VIRTUAL_PYTHONHOME="${PYTHONHOME:-}"
    unset PYTHONHOME
fi                                                                                                                                                   

if [ -z "${VIRTUAL_ENV_DISABLE_PROMPT:-}" ] ; then
    _OLD_VIRTUAL_PS1="${PS1:-}"
    PS1="("'(venv) '") ${PS1:-}"
    export PS1 
fi
# [...]

cc @vsajip

[StanFromIreland]

This issue should be closed, it only affects 3.12 which no longer allows bugfixes.

[hugovk]

Reproducible in 3.12:

❯ docker run --rm -it python:3.12 bash
root@9131fb969a1b:/# python3 --version
Python 3.12.10
root@9131fb969a1b:/# python -m venv venv
root@9131fb969a1b:/# source venv/bin/activate
((venv) ) root@9131fb969a1b:/#
exit

But not 3.13:

❯ docker run --rm -it python:3.13 bash
root@05795675a6a3:/# python3 --version
Python 3.13.3
root@05795675a6a3:/# python -m venv venv
root@05795675a6a3:/# source venv/bin/activate
(venv) root@05795675a6a3:/#
exit

[StanFromIreland]

Very unfortunate, introduced just days before the deadline, and very visible too :-(

[hugovk]

All the more reason to upgrade to Python 3.13, and get all the other bugfixes too 👍

[gernophil]

Came here pretty late. Is this only a cosmetic bug or does it have any consequences?

[hugovk]

Likely only cosmetic.