Fix --lock for multiplatform via sdists. (#1689)

Previously multiplatform PEXes built via a `--lock` that selected sdists
would fail to gather the wheel built from the sdist for each applicable
platform.

Fixes #1688

pex/resolver.py

@@ -35,17 +35,7 @@
 from pex.util import CacheHelper, DistributionHelper
 
 if TYPE_CHECKING:
-    from typing import (
-        DefaultDict,
-        Dict,
-        Iterable,
-        Iterator,
-        List,
-        Mapping,
-        Optional,
-        Sequence,
-        Tuple,
-    )
+    from typing import DefaultDict, Iterable, Iterator, List, Mapping, Optional, Sequence, Tuple
 
     import attr  # vendor:skip
 
@@ -82,7 +72,7 @@ def lock(self):
                 DistMetadata.for_dist(install_request.wheel_path)
                 for install_request in itertools.chain(
                     tuple(self.download_result.install_requests()),
-                    build_results.values(),
+                    itertools.chain.from_iterable(build_results.values()),
                 )
             )
         locked_resolve = LockedResolve.create(
@@ -544,9 +534,11 @@ def _categorize_build_requests(
         build_requests,  # type: Iterable[BuildRequest]
         dist_root,  # type: str
     ):
-        # type: (...) -> Tuple[Iterable[BuildRequest], Dict[str, InstallRequest]]
+        # type: (...) -> Tuple[Iterable[BuildRequest], DefaultDict[str, OrderedSet[InstallRequest]]]
         unsatisfied_build_requests = []
-        build_results = {}  # type: Dict[str, InstallRequest]
+        build_results = defaultdict(
+            OrderedSet
+        )  # type: DefaultDict[str, OrderedSet[InstallRequest]]
         for build_request in build_requests:
             build_result = build_request.result(dist_root)
             if not build_result.is_built:
@@ -560,7 +552,7 @@ def _categorize_build_requests(
                         build_request.source_path, build_result.dist_dir
                     )
                 )
-                build_results[build_request.source_path] = build_result.finalize_build()
+                build_results[build_request.source_path].add(build_result.finalize_build())
         return unsatisfied_build_requests, build_results
 
     def _spawn_wheel_build(
@@ -589,7 +581,7 @@ def build_wheels(
         workspace=None,  # type: Optional[str]
         max_parallel_jobs=None,  # type: Optional[int]
     ):
-        # type: (...) -> Mapping[str, InstallRequest]
+        # type: (...) -> Mapping[str, OrderedSet[InstallRequest]]
 
         if not build_requests:
             # Nothing to build or install.
@@ -613,7 +605,7 @@ def build_wheels(
                 error_handler=Raise(Untranslatable),
                 max_jobs=max_parallel_jobs,
             ):
-                build_results[build_result.request.source_path] = build_result.finalize_build()
+                build_results[build_result.request.source_path].add(build_result.finalize_build())
 
         return build_results
 
@@ -718,7 +710,7 @@ def install_distributions(
             workspace=workspace,
             max_parallel_jobs=max_parallel_jobs,
         )
-        to_install.extend(build_results.values())
+        to_install.extend(itertools.chain.from_iterable(build_results.values()))
 
         # 2. All requirements are now in wheel form: calculate any missing direct requirement
         #    project names from the wheel names.
@@ -734,8 +726,8 @@ def iter_direct_requirements():
                         yield requirement.requirement
                         continue
 
-                    install_req = build_results.get(requirement.path)
-                    if install_req is None:
+                    install_reqs = build_results.get(requirement.path)
+                    if not install_reqs:
                         raise AssertionError(
                             "Failed to compute a project name for {requirement}. No corresponding "
                             "wheel was found from amongst:\n{install_requests}".format(
@@ -747,12 +739,14 @@ def iter_direct_requirements():
                                             wheel_path=build_result.wheel_path,
                                             fingerprint=build_result.fingerprint,
                                         )
-                                        for path, build_result in build_results.items()
+                                        for path, build_results in build_results.items()
+                                        for build_result in build_results
                                     )
                                 ),
                             )
                         )
-                    yield requirement.as_requirement(dist=install_req.wheel_path)
+                    for install_req in install_reqs:
+                        yield requirement.as_requirement(dist=install_req.wheel_path)
 
             direct_requirements_by_project_name = defaultdict(
                 OrderedSet

tests/integration/cli/commands/test_issue_1688.py

@@ -0,0 +1,66 @@
+# Copyright 2022 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+import os
+import subprocess
+
+from pex.cli.testing import run_pex3
+from pex.interpreter import PythonInterpreter
+from pex.pex_info import PexInfo
+from pex.resolve import lockfile
+from pex.testing import run_pex_command
+from pex.typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from typing import Any
+
+
+def test_multiplatform_sdist(
+    tmpdir,  # type: Any
+    py27,  # type: PythonInterpreter
+    py37,  # type: PythonInterpreter
+    py310,  # type: PythonInterpreter
+):
+    # type: (...) -> None
+
+    all_interpreters = (py27, py37, py310)
+    python_path = ":".join((interp.binary for interp in all_interpreters))
+    interpreter_selection_args = [
+        "--python-path",
+        python_path,
+        "--interpreter-constraint",
+        ">=2.7,<3.11",
+    ]
+
+    lock = os.path.join(str(tmpdir), "lock")
+    run_pex3(
+        "lock",
+        "create",
+        "--style",
+        "universal",
+        "--no-wheel",
+        "psutil==5.9.0",
+        "-o",
+        lock,
+        *interpreter_selection_args
+    ).assert_success()
+    lock_file = lockfile.load(lock)
+    assert 1 == len(lock_file.locked_resolves), "Expected 1 resolve for universal style."
+    locked_resolve = lock_file.locked_resolves[0]
+    assert 1 == len(
+        locked_resolve.locked_requirements
+    ), "Expected 1 locked requirement since psutil has no dependencies"
+    locked_requirement = locked_resolve.locked_requirements[0]
+    assert 0 == len(
+        locked_requirement.additional_artifacts
+    ), "Expected just a single sdist artifact since we specified --no-wheel."
+    assert locked_requirement.artifact.url.endswith(".tar.gz"), "Expected a locked sdist URL."
+
+    pex = os.path.join(str(tmpdir), "pex")
+    run_pex_command(args=["--lock", lock, "-o", pex] + interpreter_selection_args).assert_success()
+
+    assert 3 == len(
+        PexInfo.from_pex(pex).distributions
+    ), "Expected a unique platform-specific wheel to be built for each interpreter"
+    for interp in all_interpreters:
+        subprocess.check_call(args=[interp.binary, pex, "-c", "import psutil"])