Build debian package with python3

Switch to using python 3 for building the dh-virtualenv deb.

Python2 is dead, and the existing build fails for Ubuntu 20.04 and debian
testing (specifically, python-mock and python-sphinx no longer exist).

Dockerfile

@@ -11,8 +11,8 @@ RUN apt-get update -qq -o Acquire::Languages=none \
     && env DEBIAN_FRONTEND=noninteractive apt-get install \
         -yqq --no-install-recommends -o Dpkg::Options::=--force-unsafe-io \
         build-essential debhelper devscripts equivs lsb-release libparse-debianchangelog-perl \
-        python python-setuptools python-pip python-dev \
-        python-sphinx python-mock dh-exec dh-python python-sphinx-rtd-theme \
+        python3 python3-setuptools python3-pip python3-dev \
+        python3-sphinx python3-mock dh-exec dh-python python3-sphinx-rtd-theme \
     && apt-get clean && rm -rf "/var/lib/apt/lists"/*
 WORKDIR /dpkg-build
 COPY ./ ./

debian/control

@@ -2,22 +2,22 @@ Source: dh-virtualenv
 Section: python
 Priority: optional
 Maintainer: Jyrki Pulliainen <[email protected]>
-Build-Depends: debhelper (>= 9), python(>= 2.6.6-3~),
- python-setuptools, python-sphinx, python-mock, dh-exec, dh-python,
+Build-Depends: debhelper (>= 9), python3,
+ python3-setuptools, python3-sphinx, python3-mock, dh-exec, dh-python,
 # python-sphinx-rtd-theme doesn't exist in distributions
 # predating Debian Jessie and Ubuntu Xenial. On these legacy
 # systems:
 # 1. Comment the dependency below.
 # 2. pip install sphinx_rtd_theme.
 # 3. Proceed with your build process (typically dpkg-build).
 # See https://github.com/spotify/dh-virtualenv/issues/230
- python-sphinx-rtd-theme
+ python3-sphinx-rtd-theme
 Standards-Version: 4.2.1
 Homepage: http://www.github.com/spotify/dh-virtualenv
 
 Package: dh-virtualenv
 Architecture: all
-Depends: ${python:Depends}, ${misc:Depends}, ${sphinxdoc:Depends},
+Depends: ${python3:Depends}, ${misc:Depends}, ${sphinxdoc:Depends},
  virtualenv | python-virtualenv (>= 1.7) | python3-venv
 Description: wrap and build python packages using virtualenv
  This package provides a dh sequencer that helps you to deploy your

debian/rules

@@ -6,7 +6,7 @@ ifeq (,$(findstring nodoc, $(DEB_BUILD_OPTIONS)))
 endif
 
 %:
-	dh $@ --buildsystem=pybuild --with python2 $(DH_ARGS)
+	dh $@ --buildsystem=pybuild --with python3 $(DH_ARGS)
 
 override_dh_auto_clean:
 	rm -rf doc/_build
@@ -20,7 +20,7 @@ override_dh_auto_build:
 
 ifeq (,$(findstring nodoc, $(DEB_BUILD_OPTIONS)))
 override_dh_installdocs:
-	python setup.py build_sphinx
+	python3 setup.py build_sphinx
 	dh_installdocs doc/_build/html
 
 # Make Sphinxdocs build on Jessie and Xenial