fix installation issues with setuptools<64

Author: Jonathanlyj

README.md

@@ -20,7 +20,7 @@ applications that require parallel access to netCDF files.
 ### Developer Installation
 * Clone this GitHub repository
 * Make sure the above dependent software are installed.
-* In addition, [Cython](http://cython.org/), [packaging](https://pypi.org/project/packaging/) and ['wheel'](https://pypi.org/project/wheel/) are required for developer installation.
+* In addition, [Cython](http://cython.org/), [packaging](https://pypi.org/project/packaging/), [setuptools>=65](https://pypi.org/project/setuptools/) and [wheel](https://pypi.org/project/wheel/) are required for developer installation.
 * Set the environment variable `PNETCDF_DIR` to PnetCDF's installation path.
 * Make sure utility program `pnetcdf-config` is available in `$PNETCDF_DIR/bin`.
 * Run command below to install.

docs/source/installation/install.rst

@@ -46,10 +46,10 @@ Building PnetCDF-python from source
      # use Python 3.9 or later
      $ python -m venv env
      $ source env/bin/activate
-     $ pip install --upgrade pip
+     $ pip install --upgrade pip setuptools wheel packaging
 
      # install Python libraries
-     $ pip install numpy Cython setuptools wheel packaging
+     $ pip install numpy Cython
      $ env CC=/path/to/mpicc pip install mpi4py
 
      # download PnetCDF-python source code