Use flit to distribute pex.

This gets rid of the tricky setup.py setuptools and wheel bootstrapping
we were doing using pex vendored versions and gives us non-deprecated
publishing support. In the course of adding a pyproject.toml for flit,
also update pex distribution metadata to officially support Python 3.8
with 1 test tweak. CI for Python 3.8 will come in a follow-up change.

Fixes #805
Fixes #807

RELEASE.rst

@@ -15,16 +15,18 @@ local commit:
 
 ::
 
-    $ git log --stat -1
-    commit 8ffb208eb8cc597a4a486b212e0f6d3a12416a09 (HEAD -> master, tag: v1.6.5, origin/master, origin/HEAD)
+    $ git log --stat -1 v2.0.3
+    commit 6b3e12a86ae98682f1f1df468a960be6911d6557 (HEAD -> master, tag: v2.0.3, origin/master, origin/HEAD)
     Author: John Sirois <john.sirois@gmail.com>
-    Date:   Fri Mar 29 17:53:00 2019 -0700
+    Date:   Thu Dec 5 23:51:41 2019 -0800
 
-        Prepare the 1.6.5 release. (#697)
+        Prepare the 2.0.3 release. (#822)
 
-     CHANGES.rst    | 8 ++++++++
-     pex/version.py | 2 +-
-     2 files changed, 9 insertions(+), 1 deletion(-)
+        Fixes #814
+
+     CHANGES.rst    | 20 ++++++++++++++++++++
+     pex/version.py |  2 +-
+     2 files changed, 21 insertions(+), 1 deletion(-)
 
 Push to Master
 --------------
@@ -33,7 +35,7 @@ Tag, push and watch Travis CI go green:
 
 ::
 
-    $ git tag --sign -am 'Release 1.6.5' v1.6.5
+    $ git tag --sign -am 'Release 2.0.3' v2.0.3
     $ git push --tags origin HEAD
 
 PyPI Release
@@ -44,7 +46,7 @@ Upload to PyPI
 
 ::
 
-    $ python setup.py bdist_wheel sdist upload --sign
+    $ tox -e publish
 
 Dogfood
 -------
@@ -54,7 +56,7 @@ Dogfood
     $ pip install --no-cache-dir --upgrade pex
     ...
     $ pex --version
-    pex 1.6.5
+    pex 2.0.3
 
 Github Release
 ==============
@@ -67,20 +69,20 @@ Prepare binary assets
     $ tox -e package
     ...
     $ ./dist/pex --version
-    pex 1.6.5
+    pex 2.0.3
 
 Craft the Release
 -----------------
 
 Open a tab on prior release as a template:
 
--  https://github.com/pantsbuild/pex/releases/edit/v1.6.4
+-  https://github.com/pantsbuild/pex/releases/edit/v2.0.2
 
 Open a tab to construct the current:
 
--  https://github.com/pantsbuild/pex/releases/new?tag=v1.6.5
+-  https://github.com/pantsbuild/pex/releases/new?tag=v2.0.3
 
-1. Use "Release <VERSION>" as the release name (e.g. "Release 1.6.5")
+1. Use "Release <VERSION>" as the release name (e.g. "Release 2.0.3")
 2. Copy and paste the most recent CHANGES.rst section.
 3. Adapt the syntax from RestructuredText to Markdown (e.g. ``#ID <links>`` -> ``#ID``).
 4. Upload the ``pex`` artifact.
@@ -90,10 +92,11 @@ Check your work
 
 ::
 
-    $ curl -L https://github.com/pantsbuild/pex/releases/download/v1.6.5/pex -O
+    $ curl -L https://github.com/pantsbuild/pex/releases/download/v2.0.3/pex > /tmp/pex
       % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                      Dload  Upload   Total   Spent    Left  Speed
-    100   578    0   578    0     0    525      0 --:--:--  0:00:01 --:--:--   525
-    100 1450k  100 1450k    0     0   128k      0  0:00:11  0:00:11 --:--:--  139k
-    $ ./pex --version
-    pex 1.6.5
+    100   593    0   593    0     0   1222      0 --:--:-- --:--:-- --:--:--  1222
+    100 2370k  100 2370k    0     0   962k      0  0:00:02  0:00:02 --:--:-- 1383k
+    $ chmod +x /tmp/pex
+    $ /tmp/pex --version
+    pex 2.0.3

docs/conf.py

@@ -16,12 +16,13 @@
 import sys
 from datetime import datetime
 
+from pex.version import __version__ as PEX_VERSION
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 sys.path.insert(0, os.path.abspath('..'))
 
-from pex.version import __version__ as PEX_VERSION
 
 # -- General configuration ------------------------------------------------
 

pyproject.toml

@@ -0,0 +1,41 @@
+[build-system]
+requires = ["flit_core >=2,<3"]
+build-backend = "flit_core.buildapi"
+
+[tool.flit.metadata]
+module = "pex"
+author = "The PEX developers"
+author-email = "pantsbuild@gmail.com"
+home-page = "https://github.com/pantsbuild/pex"
+description-file = "README.rst"
+classifiers = [
+  "Intended Audience :: Developers",
+  "License :: OSI Approved :: Apache Software License",
+  "Operating System :: Unix",
+  "Operating System :: POSIX :: Linux",
+  "Operating System :: MacOS :: MacOS X",
+  "Programming Language :: Python",
+  "Programming Language :: Python :: 2",
+  "Programming Language :: Python :: 2.7",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3.5",
+  "Programming Language :: Python :: 3.6",
+  "Programming Language :: Python :: 3.7",
+  "Programming Language :: Python :: 3.8",
+]
+requires-python = ">=2.7,<3.9,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*"
+
+[tool.flit.metadata.requires-extra]
+# For improved subprocess robustness under python2.7.
+subprocess = ["subprocess32>=3.2.7"]
+
+[tool.flit.scripts]
+pex = "pex.bin.pex:main"
+
+[tool.flit.entrypoints."distutils.commands"]
+# Make bdist_pex available for folks who install the pex distribution.
+bdist_pex = "pex.commands.bdist_pex:bdist_pex"
+
+[tool.flit.sdist]
+include = ["CHANGES.rst"]
+

scripts/combine_coverage.py

@@ -2,6 +2,7 @@
 import sys
 
 from coverage.data import CoverageData
+
 from pex.pex_builder import BOOTSTRAP_DIR
 
 
@@ -36,7 +37,8 @@ def combine_pex_coverage(root_dir, coverage_file_iter, unlink=True):
     cov.read()
     combined.add_line_data(dict(_iter_filter(root_dir, cov.line_data())))
     combined.add_arc_data(dict(_iter_filter(root_dir, cov.arc_data())))
-    os.unlink(filename)
+    if unlink:
+      os.unlink(filename)
 
   # filter out non-pex files
   prefix = os.path.join(root_dir, 'pex/')

scripts/coverage.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-coverage run -p -m py.test tests
+coverage run -p -m pytest tests
 coverage run -p -m pex.bin.pex -v --help >&/dev/null
 coverage run -p -m pex.bin.pex -v -- scripts/do_nothing.py
 coverage run -p -m pex.bin.pex -v requests -- scripts/do_nothing.py

scripts/list_tests.py

@@ -3,6 +3,7 @@
 from __future__ import absolute_import, print_function
 
 import sys
+
 import pytest
 
 

setup.py

@@ -1,70 +0,0 @@
-# Copyright 2014 Pants project contributors (see CONTRIBUTORS.md).
-# Licensed under the Apache License, Version 2.0 (see LICENSE).
-
-import os
-
-
-# We may be executed from outside the project dir: `python pex/setup.py ...`, so ensure the
-# `setup.py` dir is on the path and we're working from here so that dist/ and build/ dirs get
-# created here and all files indicated by MANIFEST.in are found.
-__HERE = os.path.realpath(os.path.dirname(__file__))
-os.chdir(__HERE)
-
-
-with open(os.path.join(__HERE, 'README.rst')) as fp:
-  LONG_DESCRIPTION = fp.read() + '\n'
-
-
-with open(os.path.join(__HERE, 'CHANGES.rst')) as fp:
-  LONG_DESCRIPTION += fp.read()
-
-
-from pex import third_party
-third_party.install(expose=['setuptools', 'wheel'])
-
-
-from pex.third_party.setuptools import find_packages, setup
-from pex.commands.bdist_pex import bdist_pex
-from pex.version import __version__
-
-
-setup(
-  name='pex',
-  version=__version__,
-  description="The PEX packaging toolchain.",
-  long_description=LONG_DESCRIPTION,
-  long_description_content_type="text/x-rst",
-  url='https://github.com/pantsbuild/pex',
-  license='Apache License, Version 2.0',
-  zip_safe=False,
-  classifiers=[
-    'Intended Audience :: Developers',
-    'License :: OSI Approved :: Apache Software License',
-    'Operating System :: Unix',
-    'Operating System :: POSIX :: Linux',
-    'Operating System :: MacOS :: MacOS X',
-    'Programming Language :: Python',
-    'Programming Language :: Python :: 2',
-    'Programming Language :: Python :: 2.7',
-    'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.5',
-    'Programming Language :: Python :: 3.6',
-    'Programming Language :: Python :: 3.7',
-  ],
-  packages=find_packages(),
-  include_package_data=True,
-  extras_require={
-    # For improved subprocess robustness under python2.7.
-    'subprocess': ['subprocess32>=3.2.7'],
-  },
-  cmdclass={'bdist_pex': bdist_pex},  # Make bdist_pex available for _this_ setup.py.
-  entry_points={
-    'distutils.commands': [
-      # Make bdist_pex available for folks who install the pex distribution.
-      'bdist_pex = pex.commands.bdist_pex:bdist_pex',
-    ],
-    'console_scripts': [
-      'pex = pex.bin.pex:main',
-    ],
-  },
-)

tests/test_pep425tags.py

@@ -49,6 +49,10 @@ def abi_tag_unicode(self, flags, config_vars):
         assert abi_tag == base + flags + 'u'
 
     else:
+      if sys.version_info >= (3, 8):
+        # On Python >= 3.8, the m flag is no longer used: https://bugs.python.org/issue36707
+        flags = flags.replace('m', '')
+
       # On Python >= 3.3, UCS-4 is essentially permanently enabled, and
       # Py_UNICODE_SIZE is None. SOABI on these builds does not include
       # the 'u' so manual SOABI detection should not do so either.
@@ -58,6 +62,7 @@ def abi_tag_unicode(self, flags, config_vars):
         abi_tag = pex.pep425tags.get_abi_tag()
         assert abi_tag == base + flags
 
+
   def test_broken_sysconfig(self):
     """
     Test that pep425tags still works when sysconfig is broken.