update dh-virtualenv (matrix-org#7526)

Author: richvdh

changelog.d/7526.misc

@@ -0,0 +1 @@
+Update the version of dh-virtualenv we use to build debs, and add focal to the list of target distributions.

debian/build_virtualenv

@@ -36,7 +36,6 @@ esac
 dh_virtualenv \
     --install-suffix "matrix-synapse" \
     --builtin-venv \
-    --setuptools \
     --python "$SNAKE" \
     --upgrade-pip \
     --preinstall="lxml" \

docker/Dockerfile-dhvirtualenv

@@ -27,15 +27,16 @@ RUN env DEBIAN_FRONTEND=noninteractive apt-get install \
         wget
 
 # fetch and unpack the package
-RUN wget -q -O /dh-virtuenv-1.1.tar.gz https://github.com/spotify/dh-virtualenv/archive/1.1.tar.gz
-RUN tar xvf /dh-virtuenv-1.1.tar.gz
+RUN mkdir /dh-virtualenv
+RUN wget -q -O /dh-virtualenv.tar.gz https://github.com/matrix-org/dh-virtualenv/archive/matrixorg-20200519.tar.gz
+RUN tar -xv --strip-components=1 -C /dh-virtualenv -f /dh-virtualenv.tar.gz
 
 # install its build deps
-RUN cd dh-virtualenv-1.1/ \
-    && env DEBIAN_FRONTEND=noninteractive mk-build-deps -ri -t "apt-get -yqq --no-install-recommends"
+RUN cd /dh-virtualenv \
+    && env DEBIAN_FRONTEND=noninteractive mk-build-deps -ri -t "apt-get -y --no-install-recommends"
 
 # build it
-RUN cd dh-virtualenv-1.1 && dpkg-buildpackage -us -uc -b
+RUN cd /dh-virtualenv && dpkg-buildpackage -us -uc -b
 
 ###
 ### Stage 1
@@ -68,12 +69,12 @@ RUN apt-get update -qq -o Acquire::Languages=none \
         sqlite3 \
         libpq-dev
 
-COPY --from=builder /dh-virtualenv_1.1-1_all.deb /
+COPY --from=builder /dh-virtualenv_1.2~dev-1_all.deb /
 
 # install dhvirtualenv. Update the apt cache again first, in case we got a
 # cached cache from docker the first time.
 RUN apt-get update -qq -o Acquire::Languages=none \
-    && apt-get install -yq /dh-virtualenv_1.1-1_all.deb
+    && apt-get install -yq /dh-virtualenv_1.2~dev-1_all.deb
 
 WORKDIR /synapse/source
 ENTRYPOINT ["bash","/synapse/source/docker/build_debian.sh"]

scripts-dev/build_debian_packages

@@ -27,6 +27,7 @@ DISTS = (
     "ubuntu:cosmic",
     "ubuntu:disco",
     "ubuntu:eoan",
+    "ubuntu:focal",
 )
 
 DESC = '''\