Description

On Python 3.12+ (conda/miniconda environments with latest pip/setuptools), running

pip install -e ".[dev]"

or

pip install -e .

fails with:

ModuleNotFoundError: No module named 'pkg_resources'

This happens because setup.py uses the deprecated pkg_resources and modern pip uses strict build isolation (no setuptools in the temp build env by default).

Reproduction Steps

1. Fresh Python 3.12 conda env
2. git clone https://github.com/fossasia/visdom.git
3. cd visdom
4. pip install -e ".[dev]"

Expected Behavior

Should install cleanly in editable mode (as it does on Python 3.10/3.11 with older setuptools).

Proposed Fix

• Replace pkg_resources with importlib.metadata (available in stdlib since Python 3.8)
• Also fix the boolean logic in the pillow-simd fallback (get_dist() was returning True/False but being compared with is not None, causing pillow-simd to always be selected, breaking builds on macOS/ARM

This fix will make Visdom installable again for all Python >= 3.8

Environment

• OS: macOS (also happens on Linux)
• Python: 3.12
• pip/setuptools: latest

I am preparing a PR for this.