[WIP] Install Cython in isolated env using fortunate-pkg

.appveyor.yml

@@ -33,10 +33,13 @@ install:
   - "tools/build.cmd %PYTHON%\\python.exe -m pip install -r requirements/ci.txt"
 
 build_script:
-  - "tools/build.cmd %PYTHON%\\python.exe -m setup sdist bdist_wheel"
+  - "tools/build.cmd %PYTHON%\\python.exe -m pip install pep517"
+  - "tools/build.cmd %PYTHON%\\python.exe -m pep517.build --source --binary --out-dir ./dist/ ."
 
 test_script:
+  - mv aiohttp aiohttp.bak
   - "tools/build.cmd %PYTHON%\\python.exe -m pytest -c pytest.ci.ini --cov-report xml"
+  - mv aiohttp.bak aiohttp
 
 after_test:
   - "tools/build.cmd %PYTHON%\\python.exe -m codecov -f coverage.xml -X gcov"

.travis.yml

@@ -155,7 +155,6 @@ jobs:
     name: Checking Towncrier fragments
     install:
     - *upgrade_python_toolset
-    - pip install -r requirements/cython.txt
     - pip install -r requirements/ci.txt
     - pip install -r requirements/towncrier.txt
     script:
@@ -173,7 +172,6 @@ jobs:
     name: Linting source code with mypy
     install:
     - *upgrade_python_toolset
-    - pip install -r requirements/cython.txt
     - pip install -r requirements/ci.txt
     script:
     - mypy aiohttp
@@ -182,10 +180,10 @@ jobs:
     name: Verifying distribution package metadata
     install:
     - *upgrade_python_toolset
-    - pip install -r requirements/cython.txt
-    - pip install -r requirements/ci.txt -r requirements/doc.txt
+    - pip install pep517 -r requirements/ci.txt -r requirements/doc.txt
+    - python -m pep517.build --source --binary --out-dir ./dist/ .
     script:
-    - python setup.py check --metadata --restructuredtext --strict --verbose sdist bdist_wheel
+    - python -m setup check --metadata --restructuredtext --strict --verbose
     - twine check dist/*
 
   - <<: *_lint_base
@@ -230,7 +228,6 @@ jobs:
     - docker
     script:
     - ./tools/run_docker.sh "aiohttp"
-    - pip install -r requirements/cython.txt
     - pip install -r requirements/ci.txt  # to compile *.c files by Cython
     deploy:
       <<: *deploy_step

Makefile

@@ -5,7 +5,7 @@ PYXS = $(wildcard aiohttp/*.pyx)
 all: test
 
 .install-cython:
-	pip install -r requirements/cython.txt
+	pip install fortunate_pkg[pep517] cython
 	touch .install-cython
 
 aiohttp/%.c: aiohttp/%.pyx
@@ -120,7 +120,7 @@ doc-spelling:
 	@make -C docs spelling SPHINXOPTS="-W -E"
 
 install:
-	@pip install -U 'pip<19'
+	@pip install -U pip
 	@pip install -Ur requirements/dev.txt
 
 .PHONY: all build flake test vtest cov clean doc

pyproject.toml

@@ -1,3 +1,25 @@
+[build-system]
+# NOTE: Pip will install these dependencies into an isolated venv
+requires = ["fortunate-pkg[pep517] == 0.2.7"]
+
+# NOTE: Modern setuptools implements a PEP 517 backend available at:
+# build-backend = "setuptools.build_meta"
+# NOTE: But we going to use a custom one since our requirements are
+# NOTE: too project-specific.
+build-backend = "fortunate_pkg.pep517_backend"
+
+# NOTE: in-tree backend path usage is not yet implemented in pip
+# Ref: https://www.python.org/dev/peps/pep-0517/#in-tree-build-backends
+# NOTE: future config could look like this:
+# backend-path = "./build-aiohttp"
+
+[tool.fortunate-pkg.build-system]
+# NOTE: These distribution will be `pip install`ed but failure to
+# NOTE: complete this will be ignored. This will ensure that Cython is
+# NOTE: available in the build venv if the external environments
+# NOTE: allow it.
+optionally-requires = ["Cython == 0.29.6"]
+
 [tool.towncrier]
 package = "aiohttp"
 filename = "CHANGES.rst"

requirements/ci.txt

@@ -4,4 +4,4 @@ mypy-extensions==0.4.1; implementation_name=="cpython"
 
 -r ci-wheel.txt
 -r doc.txt
--e .
+.

setup.py

@@ -14,7 +14,6 @@
 
 here = pathlib.Path(__file__).parent
 
-
 if (here / '.git').exists() and not (here / 'vendor/http-parser/README.md'):
     print("Install submodules when building from git clone", file=sys.stderr)
     print("Hint:", file=sys.stderr)

tools/build-wheels.sh

@@ -46,7 +46,6 @@ echo
 echo
 echo "Compile wheels"
 for PYTHON in ${PYTHON_VERSIONS}; do
-    /opt/python/${PYTHON}/bin/pip install -r "${WORKDIR_PATH}/requirements/cython.txt"
     /opt/python/${PYTHON}/bin/pip install -r "${WORKDIR_PATH}/requirements/wheel.txt"
     /opt/python/${PYTHON}/bin/pip wheel "${SRC_DIR}/" --no-deps -w "${ORIG_WHEEL_DIR}/${PYTHON}" -v
 done
@@ -82,7 +81,6 @@ for PYTHON in ${PYTHON_VERSIONS}; do
     echo
     echo -n "Test $PYTHON: "
     /opt/python/${PYTHON}/bin/python -c "import platform; print('Building wheel for {platform} platform.'.format(platform=platform.platform()))"
-    /opt/python/${PYTHON}/bin/pip install -r ${WORKDIR_PATH}/requirements/cython.txt
     /opt/python/${PYTHON}/bin/pip install -r ${WORKDIR_PATH}/requirements/ci-wheel.txt
     /opt/python/${PYTHON}/bin/pip install "$package_name" --no-index -f "file://${WHEELHOUSE_DIR}"
     /opt/python/${PYTHON}/bin/py.test ${WORKDIR_PATH}/tests