black: target Python 3.6; longer lines to match flake8 config

Author: mr-c

cwltool.Dockerfile

@@ -4,14 +4,15 @@ RUN apk add --no-cache git gcc python3-dev libxml2-dev libxslt-dev libc-dev linu
 
 WORKDIR /cwltool
 COPY . .
-
-RUN pip install toml -rmypy-requirements.txt -rrequirements.txt
-RUN CWLTOOL_USE_MYPYC=1 MYPYPATH=mypy-stubs pip wheel --no-binary schema-salad --wheel-dir=/wheels .[deps]
+RUN CWLTOOL_USE_MYPYC=1 MYPYPATH=mypy-stubs pip wheel --no-binary schema-salad \
+	--wheel-dir=/wheels .[deps]  # --verbose
 RUN rm /wheels/schema_salad*
-RUN pip install black
+RUN pip install "black~=22.0"
+# galaxy-util 22.1.2 depends on packaging<22, but black 23.x needs packaging>22
 RUN SCHEMA_SALAD_USE_MYPYC=1 MYPYPATH=mypy-stubs pip wheel --no-binary schema-salad \
-	$(grep schema.salad requirements.txt) black --wheel-dir=/wheels
-RUN pip install --force-reinstall --no-index --no-warn-script-location --root=/pythonroot/ /wheels/*.whl
+	$(grep schema.salad requirements.txt) "black~=22.0" --wheel-dir=/wheels  # --verbose
+RUN pip install --force-reinstall --no-index --no-warn-script-location \
+	--root=/pythonroot/ /wheels/*.whl
 # --force-reinstall to install our new mypyc compiled schema-salad package
 
 FROM python:3.11-alpine as module

pyproject.toml

@@ -0,0 +1,18 @@
+[build-system]
+requires = [
+    "setuptools>=45",
+    'mypy==0.971; python_version == "3.6"',  # last version for Python 3.6
+    'mypy==0.991; python_version >= "3.7"',
+    "types-pkg_resources",
+    "types-requests",
+    "types-psutil",
+    "ruamel.yaml>=0.16.0,<0.17.22",
+    "schema-salad>=8.2.20211104054942,<9",
+    "cwl-utils >=0.19",
+    'toml',
+]
+build-backend = "setuptools.build_meta"
+
+[tool.black]
+line-length = 100
+target-version = [ "py36" ]