Fix spurious InstalledDistribution env markers.

pex/resolver.py

@@ -109,6 +109,19 @@ def __init__(self, markers_by_requirement_key):
     def to_requirement(self, dist):
         req = dist.as_requirement()
 
+        # pkg_resources.Distribution.as_requirement returns requirements in one of two forms:
+        # 1.) project_name==version
+        # 2.) project_name===version
+        # The latter form is used whenever the distribution's version is non-standard. In those
+        # cases we cannot append environment markers since `===` indicates a raw version string to
+        # the right that should not be parsed and instead should be compared literally in full.
+        # See:
+        # + https://www.python.org/dev/peps/pep-0440/#arbitrary-equality
+        # + https://github.com/pantsbuild/pex/issues/940
+        operator, _ = req.specs[0]
+        if operator == "===":
+            return req
+
         markers = OrderedSet()
 
         # Here we map any wheel python requirement to the equivalent environment marker:

pex/testing.py

@@ -110,6 +110,7 @@ def make_project(
     install_reqs=None,  # type: Optional[List[str]]
     extras_require=None,  # type: Optional[Dict[str, List[str]]]
     entry_points=None,  # type: Optional[Union[str, Dict[str, List[str]]]]
+    python_requires=None,  # type: Optional[str]
 ):
     # type: (...) -> Iterator[str]
     project_content = {
@@ -130,6 +131,7 @@ def make_project(
             install_requires=%(install_requires)r,
             extras_require=%(extras_require)r,
             entry_points=%(entry_points)r,
+            python_requires=%(python_requires)r,
             )
             """
         ),
@@ -148,6 +150,7 @@ def make_project(
         "install_requires": install_reqs or [],
         "extras_require": extras_require or {},
         "entry_points": entry_points or {},
+        "python_requires": python_requires,
     }
 
     with temporary_content(project_content, interp=interp) as td:
@@ -190,6 +193,7 @@ def built_wheel(
     install_reqs=None,  # type: Optional[List[str]]
     extras_require=None,  # type: Optional[Dict[str, List[str]]]
     interpreter=None,  # type: Optional[PythonInterpreter]
+    python_requires=None,  # type: Optional[str]
     **kwargs  # type: Any
 ):
     # type: (...) -> Iterator[str]
@@ -199,6 +203,7 @@ def built_wheel(
         zip_safe=zip_safe,
         install_reqs=install_reqs,
         extras_require=extras_require,
+        python_requires=python_requires,
     ) as td:
         builder = WheelBuilder(td, interpreter=interpreter, **kwargs)
         yield builder.bdist()

tests/test_integration.py

@@ -2348,9 +2348,13 @@ def create_platform_pex(args):
 @pytest.fixture
 def tmp_workdir():
     # type: () -> Iterator[str]
+    cwd = os.getcwd()
     with temporary_dir() as tmpdir:
         os.chdir(tmpdir)
-        yield os.path.realpath(tmpdir)
+        try:
+            yield os.path.realpath(tmpdir)
+        finally:
+            os.chdir(cwd)
 
 
 def test_tmpdir_absolute(tmp_workdir):
@@ -2393,3 +2397,19 @@ def test_tmpdir_file(tmp_workdir):
     result.assert_failure()
     assert tmpdir_file in result.error
     assert "is not a directory" in result.error
+
+
+def test_resolve_arbitrary_equality_issues_940():
+    # type: () -> None
+    with temporary_dir() as tmpdir, built_wheel(
+        name="foo",
+        version="1.0.2-fba4511",
+        python_requires=">=2.7,<=3.9,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*",
+    ) as whl:
+        pex_file = os.path.join(tmpdir, "pex")
+        results = run_pex_command(args=["-o", pex_file, whl])
+        results.assert_success()
+
+        stdout, returncode = run_simple_pex(pex_file, args=["-c", "import foo"])
+        assert returncode == 0
+        assert stdout == b""

tests/test_resolver.py

@@ -507,3 +507,18 @@ def test_install_invalid_local_distribution():
         install(
             [LocalDistribution.create(project1_wheel, fingerprint=valid_local_sdist.fingerprint)]
         )
+
+
+def test_resolve_arbitrary_equality_issues_940():
+    # type: () -> None
+    dist = create_sdist(
+        name="foo",
+        version="1.0.2-fba4511",
+        python_requires=">=2.7,<=3.9,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*",
+    )
+    resolved_distributions = local_resolve_multi(requirements=[dist])
+
+    assert len(resolved_distributions) == 1
+    requirement = resolved_distributions[0].requirement
+    assert [("===", "1.0.2-fba4511")] == requirement.specs
+    assert requirement.marker is None