Record original requirements in PEX-INFO.

Previously we recorded the post-resolve exact requirements of all
resolved distributions. This necessitated a good deal of work to recover
environment markers and still left out any top-level environment markers
specified in direct requirements / requirement files passed to Pex. Now
we record all requirements as we received them, only filling in project
name and version for local loose-source requirements in our resolve
post-processing. This saves time (~O(500ms) for medium to large PEX
builds) and fixes bugs.

Fixes pex-tool#899

pex/bin/pex.py

@@ -12,7 +12,6 @@
 import sys
 import tempfile
 from argparse import Action, ArgumentDefaultsHelpFormatter, ArgumentParser, ArgumentTypeError
-from shlex import shlex
 from textwrap import TextWrapper
 
 from pex import pex_warnings
@@ -935,12 +934,9 @@ def to_python_interpreter(full_path_or_basename):
             )
 
             for resolved_dist in resolveds:
-                log(
-                    "  %s -> %s" % (resolved_dist.requirement, resolved_dist.distribution),
-                    V=options.verbosity,
-                )
                 pex_builder.add_distribution(resolved_dist.distribution)
-                pex_builder.add_requirement(resolved_dist.requirement)
+                if resolved_dist.direct_requirement:
+                    pex_builder.add_requirement(resolved_dist.direct_requirement)
         except Unsatisfiable as e:
             die(str(e))
 

pex/environment.py

@@ -13,7 +13,7 @@
 
 from pex import dist_metadata, pex_builder, pex_warnings
 from pex.bootstrap import Bootstrap
-from pex.common import atomic_directory, die, open_zip
+from pex.common import atomic_directory, open_zip
 from pex.inherit_path import InheritPath
 from pex.interpreter import PythonInterpreter
 from pex.orderedset import OrderedSet
@@ -84,6 +84,10 @@ def create(
         return cls(requirement=requirement, required_by=required_by)
 
 
+class ResolveError(Exception):
+    """Indicates an error resolving requirements for a PEX."""
+
+
 class PEXEnvironment(object):
     class _CachingZipImporter(object):
         class _CachingLoader(object):
@@ -434,12 +438,11 @@ def _root_requirements_iter(self, reqs):
         for key, requirements in reqs_by_key.items():
             ranked_dists = self._available_ranked_dists_by_key.get(key)
             if ranked_dists is None:
-                # This can only happen in a multi-platform PEX where the original requirement had
-                # an environment marker and this environment does not satisfy that marker.
-                TRACER.log(
-                    "A distribution for {} will not be resolved in this environment.".format(key)
+                # We've winnowed down reqs_by_key to just those requirements whose environment
+                # markers apply; so, we should always have an available distribution.
+                raise ResolveError(
+                    "A distribution for {} could not be resolved in this environment.".format(key)
                 )
-                continue
             candidates = [
                 (ranked_dist, requirement)
                 for requirement in requirements
@@ -519,7 +522,7 @@ def _resolve(self, reqs):
                         )
                     )
 
-                die(
+                raise ResolveError(
                     "Failed to execute PEX file. Needed {platform} compatible dependencies for:\n"
                     "{items}".format(platform=self._interpreter.platform, items="\n".join(items))
                 )

pex/requirements.py

@@ -303,10 +303,13 @@ def parse_requirement_from_dist(
             "Failed to find a project name and version from the given wheel path: "
             "{wheel}".format(wheel=dist)
         )
+    project_name_and_specifier = ProjectNameAndSpecifier.from_project_name_and_version(
+        project_name_and_version
+    )
     return parse_requirement_from_project_name_and_specifier(
-        project_name_and_version.project_name,
+        project_name_and_specifier.project_name,
         extras=extras,
-        specifier=SpecifierSet("=={}".format(project_name_and_version.version)),
+        specifier=project_name_and_specifier.specifier,
         marker=marker,
     )