* github-actions: install missing cython package for creating sdist wheel

* remove VERSION from gitignore and keep VERSION file

makefile

@@ -18,8 +18,9 @@ CC = g++ -std=c++17
 OPT = -O3 -Wall -Wconversion -Wpedantic -Werror -Wunused-variable -Wsign-compare
 
 # determine git version/commit and release tag
-GTAG := $(shell git tag -l --sort=version:refname | tail -n1)
+GTAG := $(shell git tag -l --sort=version:refname | tail -n1 | sed "s/$^v//g")
 GHSH := $(shell git rev-parse HEAD | head -c8)
+GVSN := $(shell cat python/VERSION | tr -d ' \n')
 
 # current timestamp
 TMS = $(shell date +%Y%m%dT%H%M%S)
@@ -31,11 +32,11 @@ INST := /usr/local/bin
 # C++ and CLI tool
 
 # build exectuable
-$(EXE) : main.o
+$(EXE): check-tags $(GVSN) main.o
 	$(CC) $(OPT) main.o -o $@
 
 # build main.cpp and include git version/commit tag
-main.o : src/main.cpp $(HPP)
+main.o: src/main.cpp $(HPP)
 	@cp $< $<.cpp
 	@sed -i 's/TAGSTRING/$(GTAG)/g' $<.cpp
 	@sed -i 's/HASHSTRING/$(GHSH)/g' $<.cpp
@@ -43,13 +44,13 @@ main.o : src/main.cpp $(HPP)
 	$(CC) -c $(OPT) -I $(LIB) $<.cpp -o $@
 	@rm $<.cpp
 
-install : $(EXE)
+install: $(EXE)
 	cp $< $(INST)/
 
-uninstall : $(INST)/$(EXE)
+uninstall: $(INST)/$(EXE)
 	rm $<
 
-cpp-clean :
+cpp-clean:
 	rm -vf $(EXE)
 	rm -vf *.o
 
@@ -59,10 +60,21 @@ cpp-clean :
 check-code:
 	cppcheck --enable=all -I lib/ src/main.cpp
 
+#-----------------------------------------------------------------------------#
+# versions
+
+$(GTAG):
+	@echo "consistent versions check successful: building $(GTAG)"
+
+check-tags:
+	@echo "latest git tag:  $(GTAG)"
+	@echo "latest git hash: $(GHSH)"
+	@echo "python version:  $(GVSN)"
+
 #-----------------------------------------------------------------------------#
 # Docker
 
-docker-build :
+docker-build:
 	docker build ./ --tag imctermite:0.1
 
 docker-run:
@@ -71,7 +83,7 @@ docker-run:
 #-----------------------------------------------------------------------------#
 # python
 
-python-build:
+python-build: check-tags $(GVSN)
 	make -C python/ build-inplace
 	cp python/IMCtermite*.so ./ -v