First pass at kwlzn change suggestions

src/python/pants/backend/python/targets/python_distribution.py

@@ -13,25 +13,15 @@
 from pants.base.payload_field import PrimitiveField
 
 class PythonDistribution(PythonTarget):
-  """A Python distribution containing c/cpp extensions.
+  """A Python distribution.
 
-  :API: public
   """
 
   @classmethod
   def alias(cls):
     return 'python_distribution'
 
 
-  def __init__(self,
-               platforms=(),
-               **kwargs):
+  def __init__(self, **kwargs):
     payload = Payload()
-    payload.add_fields({
-      'platforms': PrimitiveField(tuple(maybe_list(platforms or [])))
-    })
     super(PythonDistribution, self).__init__(sources=[], payload=payload, **kwargs)
-
-    @property
-    def platforms(self):
-      return self.payload.platforms

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

@@ -40,7 +40,7 @@ def has_python_sources(tgt):
   return is_python_target(tgt) and tgt.has_sources()
 
 
-def has_python_and_c_sources(tgt):
+def is_local_python_dist(tgt):
   return isinstance(tgt, PythonDistribution)
 
 
@@ -165,14 +165,15 @@ def build_python_distribution_from_target(target, workdir):
     whl_dist = chroot_deps_contents[0]  # TODO: find better way to grab .whl from chroot 
     whl_location = os.path.join(pydist_workdir, fingerprint, '.deps', whl_dist)
     return whl_location
-  return None
+  else:
+    raise TaskError('Failed to package python distribution for target: %s', target.name)
 
 
 def dump_python_distributions(builder, dist_targets, workdir, log):
   """Dump python distribution targets into a given builder
 
   :param builder: Dump the python_distributions into this builder.
-  :param dist_targets: PythonDistribution targets to dump
+  :param dist_targets: A list of `PythonDistribution` targets to build.
   :param workdir: Working directory for python targets (./pantsd/python)
   :param log: Use this logger.
   """
@@ -181,6 +182,8 @@ def dump_python_distributions(builder, dist_targets, workdir, log):
   locations = set()
   for tgt in dist_targets:
     whl_location = build_python_distribution_from_target(tgt, workdir)
+    if whl_location in locations:
+      raise TaskError('Two wheels of the same name have been created: %s.', whl_location)
     if whl_location:
       locations.add(whl_location)
 

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

@@ -14,9 +14,8 @@
 from pants.backend.python.targets.python_binary import PythonBinary
 from pants.backend.python.tasks2.pex_build_util import (dump_python_distributions,
                                                         dump_requirements, dump_sources,
-                                                        has_python_and_c_sources,
                                                         has_python_requirements, has_python_sources,
-                                                        has_resources)
+                                                        has_resources, is_local_python_dist)
 from pants.base.build_environment import get_buildroot
 from pants.base.exceptions import TaskError
 from pants.build_graph.target_scopes import Scopes
@@ -125,7 +124,7 @@ def _create_binary(self, binary_tgt, results_dir):
               builder.add_interpreter_constraint(constraint)
         elif has_python_requirements(tgt):
           req_tgts.append(tgt)
-        elif has_python_and_c_sources(tgt):
+        elif is_local_python_dist(tgt):
           python_dist_targets.append(tgt)
 
       # Dump everything into the builder's chroot.

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

@@ -5,8 +5,7 @@
 from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
                         unicode_literals, with_statement)
 
-from pants.backend.python.tasks2.pex_build_util import (has_python_and_c_sources,
-                                                        has_python_requirements)
+from pants.backend.python.tasks2.pex_build_util import has_python_requirements, is_local_python_dist
 from pants.backend.python.tasks2.resolve_requirements_task_base import ResolveRequirementsTaskBase
 
 
@@ -20,6 +19,6 @@ def product_types(cls):
 
   def execute(self):
     req_libs = self.context.targets(has_python_requirements)
-    python_dist_targets = self.context.targets(has_python_and_c_sources)
+    python_dist_targets = self.context.targets(is_local_python_dist)
     pex = self.resolve_requirements(req_libs, python_dist_targets=python_dist_targets)
     self.context.products.register_data(self.REQUIREMENTS_PEX, pex)

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

@@ -29,7 +29,13 @@ class ResolveRequirementsTaskBase(Task):
   def prepare(cls, options, round_manager):
     round_manager.require_data(PythonInterpreter)
 
-  def resolve_requirements(self, req_libs, python_dist_targets=None):
+  def resolve_requirements(self, req_libs, local_python_dist_targets=None):
+    """Requirements resolution for PEX files.
+
+    :param req_libs: A list of :class:`PythonRequirementLibrary` targets to resolve.
+    :param local_python_dist_targets: A list of :class:`PythonDistribution` targets to resolve.
+    :returns a PEX containing target requirements and any specified python dist targets.
+    """
     with self.invalidated(req_libs) as invalidation_check:
       # If there are no relevant targets, we still go through the motions of resolving
       # an empty set of requirements, to prevent downstream tasks from having to check
@@ -48,12 +54,12 @@ def resolve_requirements(self, req_libs, python_dist_targets=None):
       if not os.path.isdir(path):
         with safe_concurrent_creation(path) as safe_path:
           self._build_requirements_pex(interpreter, safe_path, req_libs,
-                                       python_dist_targets=python_dist_targets)
+                                       local_python_dist_targets=local_python_dist_targets)
     return PEX(path, interpreter=interpreter)
 
-  def _build_requirements_pex(self, interpreter, path, req_libs, python_dist_targets=None):
+  def _build_requirements_pex(self, interpreter, path, req_libs, local_python_dist_targets=None):
     builder = PEXBuilder(path=path, interpreter=interpreter, copy=True)
     dump_requirements(builder, interpreter, req_libs, self.context.log)
-    if python_dist_targets:
-      dump_python_distributions(builder, python_dist_targets, self.workdir, self.context.log)
+    if local_python_dist_targets:
+      dump_python_distributions(builder, local_python_dist_targets, self.workdir, self.context.log)
     builder.freeze()