Modifications to build msspec-python3

- Makefile: using python -m venv to create the virtual environment
 - src/options.mk: set PYTHON to python3; add filters and rules to treat .f90 files
 - src/pip.freeze: add packages wheel and wxPython

Makefile

@@ -10,8 +10,10 @@ pybinding:
 
 venv:
 ifeq ($(NO_VENV),0)
-	@virtualenv --python=$(PYTHON_EXE) --prompt="(msspec-$(VERSION)) " $(VENV_PATH)
+#	@virtualenv --python=$(PYTHON_EXE) --prompt="(msspec-$(VERSION)) " $(VENV_PATH)
+	$(PYTHON) -m venv $(VENV_PATH) 
 	$(INSIDE_VENV) python -m ensurepip --upgrade
+	$(INSIDE_VENV) pip install -r src/pip.freeze
 endif
 
 # wget https://bootstrap.pypa.io/get-pip.py && \
@@ -24,7 +26,7 @@ endif
 install: venv pybinding wx
 	@+$(INSIDE_VENV) $(MAKE) -C src sdist
 	@+$(INSIDE_VENV) $(MAKE) -C src frontend
-	@+$(INSIDE_VENV) pip install src/dist/msspec-$(VERSION)*.whl
+	@+$(INSIDE_VENV) pip install --force-reinstall src/dist/msspec-$(VERSION)*.whl
 	@echo "Do not forget to check that $(INSTALL_PREFIX)/bin is set in your \$$PATH"
 
 

src/options.mk

@@ -1,4 +1,4 @@
-PYTHON   = python
+PYTHON   = python3
 PYMAJ    = 3
 PYMIN    = 5
 

src/pip.freeze

@@ -10,3 +10,5 @@ pycairo
 scipy
 setuptools-scm
 terminaltables
+wheel
+wxPython