Upgrade to pex 1.4.3.

This hacks around a few issues with the 1.4.x pex API. We concoct a
minimal local `Platform` to pass to `resolve` where a local interpreter
is passed to work around pex-tool/pex#511.
We also now consolidate `PythonInterpreter` construction in production
code to helper that ensures the interpreters we create are bare
(isolated) except for the specific extras we require to work around
pex-tool/pex#510.

Upgrading pex to take advantage of the worked around issues noted above
is tracked by pantsbuild#5922.

Fixes pantsbuild#5906

3rdparty/python/requirements.txt

@@ -13,7 +13,7 @@ mock==2.0.0
 packaging==16.8
 parameterized==0.6.1
 pathspec==0.5.0
-pex==1.3.2
+pex==1.4.3
 psutil==4.3.0
 pycodestyle==2.4.0
 pyflakes==2.0.0

src/python/pants/backend/python/BUILD

@@ -40,6 +40,7 @@ python_library(
   sources = ['interpreter_cache.py'],
   dependencies = [
     '3rdparty/python:pex',
+    ':pex_util',
     'src/python/pants/backend/python/targets',
     'src/python/pants/base:exceptions',
     'src/python/pants/process',
@@ -58,7 +59,6 @@ python_library(
   ]
 )
 
-
 python_library(
   name = 'python_artifact',
   sources = ['python_artifact.py'],
@@ -76,3 +76,11 @@ python_library(
   name = 'python_requirements',
   sources = ['python_requirements.py'],
 )
+
+python_library(
+  name = 'pex_util',
+  sources = ['pex_util.py'],
+  dependencies = [
+    '3rdparty/python:pex',
+  ]
+)

src/python/pants/backend/python/interpreter_cache.py

@@ -8,11 +8,12 @@
 import os
 import shutil
 
-from pex.interpreter import PythonIdentity, PythonInterpreter
+from pex.interpreter import PythonInterpreter
 from pex.package import EggPackage, Package, SourcePackage
 from pex.resolver import resolve
 from pex.variables import Variables
 
+from pants.backend.python.pex_util import create_bare_interpreter, get_local_platform
 from pants.backend.python.targets.python_target import PythonTarget
 from pants.base.exceptions import TaskError
 from pants.process.lock import OwnerPrintingInterProcessFileLock
@@ -94,19 +95,17 @@ def select_interpreter_for_targets(self, targets):
       tgts_with_compatibilities_strs = [t.address.spec for t in tgts_with_compatibilities]
       raise self.UnsatisfiableInterpreterConstraintsError(
         'Unable to detect a suitable interpreter for compatibilities: {} '
-        '(Conflicting targets: {})'.format(' && '.join(unique_compatibilities_strs),
+        '(Conflicting targets: {})'.format(' && '.join(sorted(unique_compatibilities_strs)),
                                            ', '.join(tgts_with_compatibilities_strs)))
     # Return the lowest compatible interpreter.
     return min(allowed_interpreters)
 
   def _interpreter_from_path(self, path, filters):
-    interpreter_dir = os.path.basename(path)
-    identity = PythonIdentity.from_path(interpreter_dir)
     try:
       executable = os.readlink(os.path.join(path, 'python'))
     except OSError:
       return None
-    interpreter = PythonInterpreter(executable, identity)
+    interpreter = create_bare_interpreter(executable)
     if self._matches(interpreter, filters):
       return self._resolve(interpreter)
     return None
@@ -218,6 +217,7 @@ def _resolve_and_link(self, interpreter, requirement, target_link):
     distributions = resolve(requirements=[requirement],
                             fetchers=self._python_repos.get_fetchers(),
                             interpreter=interpreter,
+                            platform=get_local_platform(),
                             context=self._python_repos.get_network_context(),
                             precedence=precedence)
     if not distributions:

src/python/pants/backend/python/pex_util.py

@@ -0,0 +1,35 @@
+# coding=utf-8
+# Copyright 2016 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
+                        unicode_literals, with_statement)
+
+from pex.interpreter import PythonInterpreter
+from pex.platforms import Platform
+
+
+def create_bare_interpreter(binary_path):
+  """Creates an interpreter for python binary at the given path.
+
+  The interpreter is bare in that it has no extras associated with it.
+
+  :returns: A bare python interpreter with no extras.
+  :rtype: :class:`pex.interpreter.PythonInterpreter`
+  """
+  # TODO(John Sirois): Replace with a more direct PythonInterpreter construction API call when
+  # https://github.com/pantsbuild/pex/issues/510 is fixed.
+  interpreter_with_extras = PythonInterpreter.from_binary(binary_path)
+  return PythonInterpreter(binary_path, interpreter_with_extras.identity, extras=None)
+
+
+def get_local_platform():
+  """Returns the name of the local platform; eg: 'linux_x86_64' or 'macosx_10_8_x86_64'.
+
+  :returns: The local platform name.
+  :rtype: str
+  """
+  # TODO(John Sirois): Kill some or all usages when https://github.com/pantsbuild/pex/issues/511
+  # is fixed.
+  current_platform = Platform.current()
+  return current_platform.platform

src/python/pants/backend/python/tasks/BUILD

@@ -3,32 +3,33 @@
 
 python_library(
   dependencies=[
-    '3rdparty/python:pex',
     '3rdparty/python/twitter/commons:twitter.common.collections',
     '3rdparty/python/twitter/commons:twitter.common.dirutil',
+    '3rdparty/python:pex',
     'src/python/pants/backend/native/subsystems',
-    'src/python/pants/backend/python:python_requirement',
-    'src/python/pants/backend/python:python_requirements',
-    'src/python/pants/backend/python:interpreter_cache',
     'src/python/pants/backend/python/subsystems',
     'src/python/pants/backend/python/targets',
     'src/python/pants/backend/python/tasks/coverage:plugin',
+    'src/python/pants/backend/python:interpreter_cache',
+    'src/python/pants/backend/python:pex_util',
+    'src/python/pants/backend/python:python_requirement',
+    'src/python/pants/backend/python:python_requirements',
     'src/python/pants/base:build_environment',
     'src/python/pants/base:exceptions',
     'src/python/pants/base:fingerprint_strategy',
     'src/python/pants/base:hash_utils',
     'src/python/pants/base:specs',
+    'src/python/pants/build_graph',
     'src/python/pants/engine:rules',
     'src/python/pants/engine:selectors',
-    'src/python/pants/build_graph',
     'src/python/pants/invalidation',
     'src/python/pants/python',
     'src/python/pants/task',
     'src/python/pants/util:contextutil',
     'src/python/pants/util:dirutil',
     'src/python/pants/util:fileutil',
-    'src/python/pants/util:meta',
     'src/python/pants/util:memo',
+    'src/python/pants/util:meta',
     'src/python/pants/util:objects',
     'src/python/pants/util:process_handler',
     'src/python/pants/util:xml_parser',

src/python/pants/backend/python/tasks/pex_build_util.py

@@ -11,6 +11,7 @@
 from pex.resolver import resolve
 from twitter.common.collections import OrderedSet
 
+from pants.backend.python.pex_util import get_local_platform
 from pants.backend.python.subsystems.python_setup import PythonSetup
 from pants.backend.python.targets.python_binary import PythonBinary
 from pants.backend.python.targets.python_distribution import PythonDistribution
@@ -150,7 +151,7 @@ def dump_requirement_libs(builder, interpreter, req_libs, log, platforms=None):
                     Defaults to the platforms specified by PythonSetup.
   """
   reqs = [req for req_lib in req_libs for req in req_lib.requirements]
-  dump_requirements(builder, interpreter, reqs, log, platforms)
+  dump_requirements(builder, interpreter, reqs, log, platforms=platforms)
 
 
 def dump_requirements(builder, interpreter, reqs, log, platforms=None):
@@ -212,7 +213,7 @@ def _resolve_multi(interpreter, requirements, platforms, find_links):
       requirements=[req.requirement for req in requirements],
       interpreter=interpreter,
       fetchers=fetchers,
-      platform=None if platform == 'current' else platform,
+      platform=get_local_platform() if platform == 'current' else platform,
       context=python_repos.get_network_context(),
       cache=requirements_cache_dir,
       cache_ttl=python_setup.resolver_cache_ttl,

src/python/pants/backend/python/tasks/python_binary_create.py

@@ -132,7 +132,8 @@ def _create_binary(self, binary_tgt, results_dir):
       # We need to ensure that we are resolving for only the current platform if we are
       # including local python dist targets that have native extensions.
       build_for_current_platform_only_check(self.context.targets())
-      dump_requirement_libs(builder, interpreter, req_tgts, self.context.log, binary_tgt.platforms)
+      dump_requirement_libs(builder, interpreter, req_tgts, self.context.log,
+                            platforms=binary_tgt.platforms)
 
       # Build the .pex file.
       pex_path = os.path.join(results_dir, '{}.pex'.format(binary_tgt.name))

src/python/pants/backend/python/tasks/select_interpreter.py

@@ -8,9 +8,10 @@
 import hashlib
 import os
 
-from pex.interpreter import PythonIdentity, PythonInterpreter
+from pex.interpreter import PythonInterpreter
 
 from pants.backend.python.interpreter_cache import PythonInterpreterCache
+from pants.backend.python.pex_util import create_bare_interpreter
 from pants.backend.python.subsystems.python_setup import PythonSetup
 from pants.backend.python.targets.python_target import PythonTarget
 from pants.base.fingerprint_strategy import DefaultFingerprintHashingMixin, FingerprintStrategy
@@ -39,6 +40,10 @@ def compute_fingerprint(self, python_target):
 class SelectInterpreter(Task):
   """Select an Python interpreter that matches the constraints of all targets in the working set."""
 
+  @classmethod
+  def implementation_version(cls):
+    return super(SelectInterpreter, cls).implementation_version() + [('SelectInterpreter', 2)]
+
   @classmethod
   def subsystem_dependencies(cls):
     return super(SelectInterpreter, cls).subsystem_dependencies() + (PythonSetup, PythonRepos)
@@ -51,9 +56,11 @@ def execute(self):
     python_tgts = self.context.targets(lambda tgt: isinstance(tgt, PythonTarget))
     fs = PythonInterpreterFingerprintStrategy()
     with self.invalidated(python_tgts, fingerprint_strategy=fs) as invalidation_check:
-      if PythonSetup.global_instance().interpreter_search_paths and PythonInterpreterCache.pex_python_paths():
-        self.context.log.warn("Detected both PEX_PYTHON_PATH and --python-setup-interpreter-search-paths. "
-                              "Ignoring --python-setup-interpreter-search-paths.")
+      if (PythonSetup.global_instance().interpreter_search_paths
+          and PythonInterpreterCache.pex_python_paths()):
+        self.context.log.warn("Detected both PEX_PYTHON_PATH and "
+                              "--python-setup-interpreter-search-paths. Ignoring "
+                              "--python-setup-interpreter-search-paths.")
       # If there are no relevant targets, we still go through the motions of selecting
       # an interpreter, to prevent downstream tasks from having to check for this special case.
       if invalidation_check.all_vts:
@@ -75,7 +82,7 @@ def _create_interpreter_path_file(self, interpreter_path_file, targets):
     interpreter = interpreter_cache.select_interpreter_for_targets(targets)
     safe_mkdir_for(interpreter_path_file)
     with open(interpreter_path_file, 'w') as outfile:
-      outfile.write(b'{}\t{}\n'.format(interpreter.binary, str(interpreter.identity)))
+      outfile.write(b'{}\n'.format(interpreter.binary))
       for dist, location in interpreter.extras.items():
         dist_name, dist_version = dist
         outfile.write(b'{}\t{}\t{}\n'.format(dist_name, dist_version, location))
@@ -87,9 +94,9 @@ def _interpreter_path_file(self, target_set_id):
   def _get_interpreter(interpreter_path_file):
     with open(interpreter_path_file, 'r') as infile:
       lines = infile.readlines()
-      binary, identity = lines[0].strip().split('\t')
-      extras = {}
+      binary = lines[0].strip()
+      interpreter = create_bare_interpreter(binary)
       for line in lines[1:]:
         dist_name, dist_version, location = line.strip().split('\t')
-        extras[(dist_name, dist_version)] = location
-    return PythonInterpreter(binary, PythonIdentity.from_path(identity), extras)
+        interpreter = interpreter.with_extra(dist_name, dist_version, location)
+      return interpreter

tests/python/pants_test/backend/python/tasks/test_python_run_integration.py

@@ -191,20 +191,21 @@ def test_pex_resolver_blacklist_integration(self):
       return
     pex = os.path.join(os.getcwd(), 'dist', 'test_bin.pex')
     try:
-      pants_ini_config = {'python-setup': {'resolver_blacklist': {"functools32": "CPython>3"}}}
+      pants_ini_config = {'python-setup': {'resolver_blacklist': {'functools32': 'CPython>3'}}}
+      target_address_base = os.path.join(self.testproject, 'resolver_blacklist_testing')
       # clean-all to ensure that Pants resolves requirements for each run.
       pants_binary_36 = self.run_pants(
-        command=['clean-all', 'binary', '{}:test_bin'.format(os.path.join(self.testproject,'resolver_blacklist_testing'))],
+        command=['clean-all', 'binary', '{}:test_bin'.format(target_address_base)],
         config=pants_ini_config
       )
       self.assert_success(pants_binary_36)
       pants_run_36 = self.run_pants(
-        command=['clean-all', 'run', '{}:test_bin'.format(os.path.join(self.testproject,'resolver_blacklist_testing'))],
+        command=['clean-all', 'run', '{}:test_bin'.format(target_address_base)],
         config=pants_ini_config
       )
       self.assert_success(pants_run_36)
       pants_run_27 = self.run_pants(
-        command=['clean-all', 'run', '{}:test_py2'.format(os.path.join(self.testproject,'resolver_blacklist_testing'))],
+        command=['clean-all', 'run', '{}:test_py2'.format(target_address_base)],
         config=pants_ini_config
       )
       self.assert_success(pants_run_27)