Error at CMake Configure time for missing python packages

Wheel, setuptools and optionall venv are requred.
Installing into --user automatically would fail in some cases, and installing not into user into a not-generated venv is bad form.

Closes #639

.github/workflows/Windows.yml

@@ -96,6 +96,12 @@ jobs:
       with:
         python-version: ${{ env.PYTHON }}
 
+    - name: Install python dependencies
+      if: ${{ env.PYTHON != '' && env.BUILD_SWIG_PYTHON == 'ON' }}
+      run: |
+        python3 -m pip install --upgrade wheel
+        python3 -m pip install --upgrade setuptools
+
     - name: Add custom problem matchers for annotations
       run: echo "::add-matcher::.github/problem-matchers.json"
 

README.md

@@ -75,6 +75,7 @@ Optionally:
 + [cpplint](https://github.com/cpplint/cpplint) for linting code
 + [Doxygen](http://www.doxygen.nl/) to build the documentation
 + [Python](https://www.python.org/) `>= 3.7` for python integration
+  + With `setuptools`, `wheel` and optionally `venv` python packages installed
 + [swig](http://www.swig.org/) `>= 4.0.2` for python integration
   + Swig `4.x` will be automatically downloaded by CMake if not provided (if possible).
 + [FLAMEGPU2-visualiser](https://github.com/FLAMEGPU/FLAMEGPU2-visualiser) dependencies
@@ -159,8 +160,8 @@ cmake --build . --target all
 | `CMAKE_BUILD_TYPE`       | `Release`/`Debug`/`MinSizeRel`/`RelWithDebInfo` | Select the build configuration for single-target generators such as `make`   |
 | `SEATBELTS`              | `ON`/`OFF`        | Enable / Disable additional runtime checks which harm performance but increase usability. Default `ON`     |
 | `CUDA_ARCH`              | `"52 60 70 80"`   | Select [CUDA Compute Capabilities](https://developer.nvidia.com/cuda-gpus) to build/optimise for, as a space or `;` separated list. Defaults to `""` |
-| `BUILD_SWIG_PYTHON`      | `ON`/`OFF`        | Enable Python target `pyflamegpu` via Swig. Default `OFF`                                                  |
-| `BUILD_SWIG_PYTHON_VENV` | `ON`/`OFF`        | Use a python `venv` when building the python Swig target. Default `ON`.                                    |
+| `BUILD_SWIG_PYTHON`      | `ON`/`OFF`        | Enable Python target `pyflamegpu` via Swig. Default `OFF`. Python packages `setuptools` & `wheel` required |
+| `BUILD_SWIG_PYTHON_VENV` | `ON`/`OFF`        | Use a python `venv` when building the python Swig target. Default `ON`. Python package `venv` required     |
 | `BUILD_TESTS`            | `ON`/`OFF`        | Build the C++/CUDA test suite. Default `OFF`.                                                              |
 | `BUILD_TESTS_DEV`        | `ON`/`OFF`        | Build the reduced-scope development test suite. Default `OFF`                                              |
 | `VISUALISATION`          | `ON`/`OFF`        | Enable Visualisation. Default `OFF`.                                                                       |

swig/python/CMakeLists.txt

@@ -218,8 +218,7 @@ file(GENERATE
 	OUTPUT ${PYTHON_LIB_OUTPUT_DIRECTORY}/${PYTHON_MODULE_NAME}/__init__.py
 	INPUT ${PYTHON_LIB_TEMP_DIRECTORY}/__init__.py.in)
 
-# Function to find if python module MODULE_NAME is available, if not then install it to the Python user install directory.
-# @todo - we should not be performing user installs/ upgrades of setuptools/wheel. See https://github.com/FLAMEGPU/FLAMEGPU2/issues/639
+# Function to find if python module MODULE_NAME is available, and error if it is not available.
 function(search_python_module MODULE_NAME)
   execute_process(
     COMMAND ${Python3_EXECUTABLE} -c "import ${MODULE_NAME}; print(${MODULE_NAME}.__version__) if hasattr(${MODULE_NAME}, '__version__') else print('Unknown');"
@@ -231,16 +230,14 @@ function(search_python_module MODULE_NAME)
   if(${_RESULT} STREQUAL "0")
     message(STATUS "Found python module: ${MODULE_NAME} (version \"${MODULE_VERSION}\")")
   else()
-    message(WARNING "Can't find python module \"${MODULE_NAME}\", user install it using pip...")
-    execute_process(
-      COMMAND ${Python3_EXECUTABLE} -m pip install --upgrade --user ${MODULE_NAME}
-      OUTPUT_STRIP_TRAILING_WHITESPACE
-      )
+    message(FATAL_ERROR 
+      "  Unable to find required python module \"${MODULE_NAME}\".\n"
+      "  Please install this to your python environment, e.g.\n"
+      "    python3 -m pip install ${MODULE_NAME}")
   endif()
 endfunction()
 
-# Look for required python modules to build the python module
-# @todo - Do not install into the --user see https://github.com/FLAMEGPU/FLAMEGPU2/issues/639. Either error, or let python error saying wheel is missing instead (or create and use a venv).
+# Look for required python modules to build the python module, error if they are not found.
 search_python_module(setuptools)
 search_python_module(wheel)
 
@@ -383,8 +380,8 @@ add_dependencies(${PYTHON_MODULE_TARGET_NAME} ${PYTHON_SWIG_TARGET_NAME})
 
 # Build Virtual Environment for python testing and install the packaged wheel
 if(BUILD_SWIG_PYTHON_VENV)
-	# Look for python module venv
-	search_python_module(venv) # @todo - do not install if missing, configuration error instead?
+	# Look for python module venv, error if not found
+	search_python_module(venv)
 	# Testing using a virtual environment
 	set(VENV_EXECUTABLE ${Python3_EXECUTABLE} -m venv)
 	set(VENV_DIR ${PYTHON_LIB_OUTPUT_DIRECTORY}/venv)