ci : update + packages (#146)

* Add simple Debian package

* Update CI configuration

* Add cpack Deb package for libggwave-dev

* Add `make deb` top level target and CI job

* Ensure `make deb` packages are deterministic

Update CMakeLists.txt to make cpack generated Debian packages
deterministic build outputs by:
- Setting SOURCE_DATE_EPOCH to 0
- Executing `git log -1 --pretty=%ct` and storing the result in
  SOURCE_DATE_EPOCH, overriding 0
- Export SOURCE_DATE_EPOCH to the environment
- Explicitly prefix the execution of the cpack command in the custom
  target `deb_c_library` with SOURCE_DATE_EPOCH

Update `README.md-tmpl.md` and `README.md` to document new `make deb`
target.

The Makefile for the Python bindings already handle deterministic
building with the same strategy.

* libc6, not libc

bindings/python/Makefile

@@ -1,12 +1,29 @@
 default: build
 
+PKG_NAME := ggwave
+DEST := dist/
+VER := $(shell cat setup.py | grep version |cut -d\"  -f2)
+VERSION := $(strip $(VER))
+ORIG_TGZ := $(PKG_NAME)_$(VERSION).orig.tar.gz
+ARCH := $(shell dpkg --print-architecture)
+DEB_BUILD_OPTIONS := nocheck
+DEB_BUILD_DIR := $(DEST)$(PKG_NAME)-$(VERSION)
+DEB_VER := 0
+DEB := python3-$(PKG_NAME)_$(VERSION)-$(DEB_VER)_$(ARCH).deb
+SOURCE_DATE_EPOCH := $(shell git log -1 --pretty=%ct)
+SOURCE_PKG_CMD := python -m build --sdist
+DEB_BUILD_CMD := dpkg-buildpackage -rfakeroot -uc -us
+COGAPP ?= $(shell which cog || which cogapp)
+
 .PHONY:
 ggwave:
 	# create a clean (maybe updated) copy of ggwave src
 	rm -rf ggwave && mkdir ggwave && cp -r ../../include ggwave/ && cp -r ../../src ggwave/
 
+deps:
+	echo python -m pip install cogapp cython twine
+
 pyggwave.bycython.cpp: ggwave.pyx cggwave.pxd
-	python -m pip install cython
 	cython --cleanup=3 --cplus ggwave.pyx -o ggwave.bycython.cpp
 
 # To build package, README.rst is needed, because it goes into long description of package,
@@ -17,12 +34,30 @@ pyggwave.bycython.cpp: ggwave.pyx cggwave.pxd
 
 BUILD_SOURCE_FILES=ggwave pyggwave.bycython.cpp setup.py
 
+$(DEST)$(DEB): $(DEST)$(ORIG_TGZ)
+	-rm -r $(DEB_BUILD_DIR)
+	tar -C $(DEST) -xf $(DEST)$(ORIG_TGZ)
+	cp -arp debian $(DEB_BUILD_DIR)
+	cd $(DEB_BUILD_DIR) && \
+	DEB_BUILD_OPTIONS=$(DEB_BUILD_OPTIONS) $(DEB_BUILD_CMD)
+
+deb_sdist: $(BUILD_SOURCE_FILES) README.rst
+	SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH) $(SOURCE_PKG_CMD)
+	mv $(DEST)$(PKG_NAME)-$(VERSION).tar.gz $(DEST)$(ORIG_TGZ)
+
+_deb:
+	@$(eval COGAPP=cogapp)
+
+deb: _deb deb_sdist $(DEST)$(DEB)
+	dpkg --contents $(DEST)$(DEB)
+	ls -alh $(DEST)*$(PKG_NAME)*
+	sha256sum $(DEST)$(DEB)
+
 buildWithoutREADME.rst: ${BUILD_SOURCE_FILES}
 	GGWAVE_OMIT_README_RST=1 python setup.py build_ext -i
 
 README.rst: buildWithoutREADME.rst README-tmpl.rst
-	python -m pip install cogapp
-	cog -d -o README.rst README-tmpl.rst
+	$(COGAPP) -d -o README.rst README-tmpl.rst
 
 BUILD_FILES=${BUILD_SOURCE_FILES} README.rst