[build] modernize build-frontend: python setup.py develop/install -> [uv ]pip install --no-build-isolation [-e ]. (#156027)

Modernize the development installation:

```bash
# python setup.py develop
python -m pip install --no-build-isolation -e .

# python setup.py install
python -m pip install --no-build-isolation .
```

Now, the `python setup.py develop` is a wrapper around `python -m pip install -e .` since `setuptools>=80.0`:

- pypa/setuptools#4955

`python setup.py install` is deprecated and will emit a warning during run. The warning will become an error on October 31, 2025.

- 9c4d383631/setuptools/command/install.py (L58-L67)

> ```python
> SetuptoolsDeprecationWarning.emit(
>     "setup.py install is deprecated.",
>     """
>     Please avoid running ``setup.py`` directly.
>     Instead, use pypa/build, pypa/installer or other
>     standards-based tools.
>     """,
>     see_url="https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html",
>     due_date=(2025, 10, 31),
> )
> ```

- pypa/setuptools#3849

Additional Resource:

- [Why you shouldn't invoke setup.py directly](https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html)

Pull Request resolved: https://github.com/pytorch/pytorch/pull/156027
Approved by: https://github.com/ezyang

benchmarks/README.md

@@ -8,12 +8,12 @@ It also provides mechanisms to compare PyTorch with other frameworks.
 Make sure you're on a machine with CUDA, torchvision, and pytorch installed. Install in the following order:
 ```
 # Install torchvision. It comes with the pytorch stable release binary
-pip3 install torch torchvision
+python -m pip install torch torchvision
 
 # Install the latest pytorch master from source.
 # It should supersede the installation from the release binary.
 cd $PYTORCH_HOME
-python setup.py build develop
+python -m pip install --no-build-isolation -v -e .
 
 # Check the pytorch installation version
 python -c "import torch; print(torch.__version__)"

benchmarks/functional_autograd_benchmark/README.md

@@ -17,8 +17,8 @@ export DEBUG=0
 export OMP_NUM_THREADS=10
 
 # Compile pytorch with the base revision
-git checkout master
-python setup.py develop
+git checkout main
+python -m pip install --no-build-isolation -v -e .
 
 # Install dependencies:
 # Scipy is required by detr
@@ -32,7 +32,7 @@ python functional_autograd_benchmark.py --output before.txt
 # Compile pytorch with your change
 popd
 git checkout your_feature_branch
-python setup.py develop
+python -m pip install --no-build-isolation -v -e .
 
 # Run the benchmark for the new version
 pushd benchmarks/functional_autograd_benchmark

benchmarks/operator_benchmark/README.md

@@ -20,7 +20,7 @@ Key Features:
 The instruction below installs a cpp\_extension for PyTorch and it is required to run the benchmark suite.
 ```bash
 cd pt_extension
-python setup.py install
+python -m pip install .
 ```
 
 ## How to run the benchmarks:

benchmarks/sparse/test_csr.sh

@@ -11,7 +11,7 @@ export USE_MKL=1
 CMAKE_ONLY=1 python setup.py build
 ccmake build  # or cmake-gui build
 
-python setup.py install
+python -m pip install --no-build-isolation -v .
 
 cd benchmarks
 echo "!! SPARSE SPMM TIME BENCHMARK!! " >> $OUTFILE
@@ -28,7 +28,7 @@ echo "----- USE_MKL=0 ------" >> $OUTFILE
 rm -rf build
 
 export USE_MKL=0
-python setup.py install
+python -m pip install --no-build-isolation -v .
 
 cd benchmarks
 for dim0 in 1000 5000 10000; do