try poetry again

.ci/scripts/test_old_deps.sh

@@ -8,11 +8,63 @@ export DEBIAN_FRONTEND=noninteractive
 set -ex
 
 apt-get update
-apt-get install -y python3 python3-dev python3-venv python3-pip libxml2-dev libxslt-dev xmlsec1 zlib1g-dev tox libjpeg-dev libwebp-dev
+apt-get install -y \
+        python3 python3-dev python3-pip python3-venv pipx \
+        libxml2-dev libxslt-dev xmlsec1 zlib1g-dev libjpeg-dev libwebp-dev
 
 export LANG="C.UTF-8"
 
 # Prevent virtualenv from auto-updating pip to an incompatible version
 export VIRTUALENV_NO_DOWNLOAD=1
 
-exec tox -e py3-old
+# I'd prefer to use something like this
+#   https://github.com/python-poetry/poetry/issues/3527
+#   https://github.com/pypa/pip/issues/8085
+# rather than this sed script. But that's an Opinion.
+
+# patch the project definitions in-place
+# replace all lower bounds with exact bounds
+# delete all lines referring to psycopg2 --- so no postgres support
+# but make the pyopenssl 17.0, which can work against an
+# OpenSSL 1.1 compiled cryptography (as older ones don't compile on Travis).
+
+sed -i-backup \
+   -e "s/[~>]=/==/g" \
+   -e "/psycopg2/d" \
+   -e 's/pyOpenSSL = "==16.0.0"/pyOpenSSL = "==17.0.0"/' \
+   -e '/systemd/d' \
+   pyproject.toml
+
+pip install --user toml
+
+REMOVE_DEV_DEPENDENCIES="
+import toml
+with open('pyproject.toml', 'r') as f:
+    data = toml.loads(f.read())
+
+from pprint import pprint
+pprint(data)
+
+del data['tool']['poetry']['dev-dependencies']
+
+with open('pyproject.toml', 'w') as f:
+    data = toml.dump(data, f)
+"
+python3 -c "$REMOVE_DEV_DEPENDENCIES"
+
+# There are almost certainly going to be dependency conflicts there, so I'm going to
+# use plain pip to install rather than poetry.
+
+# Can't pip install with -e. Error message:
+# > A "pyproject.toml" file was found, but editable mode currently requires a setup.py based build.
+# Needs PEP 660 support in poetry, sigh. See
+# https://github.com/python-poetry/poetry/issues/34#issuecomment-1055142428
+# So instead, make a virtualenv and install in there.
+
+# At the time of writing, this notes:
+#  ERROR: ldap3 2.9.1 has requirement pyasn1>=0.4.6, but you'll have pyasn1 0.1.9 which is incompatible.
+# Helpfully, pip doesn't indicate the error; it returns 0.
+# TODO: bump pyasn to >=0.4.6?
+pipx install poetry
+~/.local/bin/poetry install -E "all test"
+~/.local/bin/poetry run trial -j2 tests