`uv venv` doesn't add PyPy executables

[charliermarsh]

We don't officially support PyPy right now, this is more a note for the future, but we need to include a variety of pypy binaries / symlinks:

❯ ls .venv/bin
Activate.ps1  activate      activate.csh  activate.fish pip           pip3          pip3.9        pypy          pypy3         pypy3.9       python        python3       python3.9

[charliermarsh]

@gaborbernat - A related question: how does virtualenv "know" to create site-packages for PyPy at .venv/lib/pypy3.10/site-packages instead of .venv/lib/python3.10/site-packages? Is that encoded in virtualenv somewhere? Or is it read from the interpreter? Was trying to find it.

[gaborbernat]

That's done here https://github.com/pypa/virtualenv/blob/main/src/virtualenv/create/via_global_ref/builtin/pypy/pypy3.py#L31 and https://github.com/pypa/virtualenv/blob/main/src/virtualenv/create/via_global_ref/builtin/pypy/common.py#L41. It knows to do that just for PyPy because of https://github.com/pypa/virtualenv/blob/main/src/virtualenv/create/via_global_ref/builtin/pypy/common.py#L13. The purelib/platlib paths are using the sysconfig information, which is inquired as part of https://github.com/pypa/virtualenv/blob/main/src/virtualenv/discovery/py_info.py#L80-L103.

Note that .venv/lib/pypy3.10/site-packages is often refered to as purelib, and in CPython by default this aligns up with platlib, but CPython allows distributions to move this to their desired path. So ultimately, the question is: When you say .venv/lib/pypy3.10/site-packages are you refering to platlib or purelib?

[charliermarsh]

Ah yeah, I'm referring to purelib. (Though I haven't really done the work yet to understand what happens when you, e.g., pip uninstall and purelib and platlib are not the same thing.)

If sysconfig is returning the purelib and platlib paths for the invoked interpreter, where / how do those get translated to paths for the virtualenv? E.g.:

>>> sysconfig.get_paths(scheme="venv")
{'stdlib': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/lib/python3.12', 'platstdlib': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/lib/python3.12', 'purelib': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/lib/python3.12/site-packages', 'platlib': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/lib/python3.12/site-packages', 'include': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/include/python3.12', 'platinclude': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/include/python3.12', 'scripts': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0/bin', 'data': '/Users/crmarsh/.local/share/rtx/installs/python/3.12.0'}

[gaborbernat]

That depends. You can get the schema and inject your config vars of sys.prefix to calculate where it should go.

[gaborbernat]

See https://github.com/pypa/virtualenv/blob/main/src/virtualenv/discovery/py_info.py#L224

[charliermarsh]

Thank you!

[charliermarsh]

Filed some info in #2095. (No obligation to chime in there.)

[charliermarsh]

@edgarrmondragon - when you’re in a PyPy virtualenv, do you typically invoke Python as “pypy” or “python”? I’m trying to make some decisions around this with respect to #2316.

[edgarrmondragon]

@edgarrmondragon - when you’re in a PyPy virtualenv, do you typically invoke Python as “pypy” or “python”? I’m trying to make some decisions around this with respect to #2316.

Actually, always as python or python3.x