install poetry and run export

docker/Dockerfile-dhvirtualenv

@@ -85,6 +85,13 @@ RUN apt-get update -qq -o Acquire::Languages=none \
         libpq-dev \
         xmlsec1
 
+RUN pip3 install -U \
+    pip \
+    setuptools \
+    wheel
+
+RUN pip3 install poetry==1.2.0b1
+
 COPY --from=builder /dh-virtualenv_1.2.2-1_all.deb /
 
 # install dhvirtualenv. Update the apt cache again first, in case we got a

docker/build_debian.sh

@@ -11,6 +11,9 @@ DIST=$(cut -d ':' -f2 <<< "${distro:?}")
 cp -aT /synapse/source /synapse/build
 cd /synapse/build
 
+# Export a requirements.txt file for the dh-virtualenv to use
+poetry export --extras "all test" -o requirements.txt
+
 # if this is a prerelease, set the Section accordingly.
 #
 # When the package is later added to the package repo, reprepro will use the