Eliminate warnings for default use.

Previously `pex` would warn for default usage scenarios under both
Python 3.11 and Python 3.12. For Python 3.12, the `--pip-version`
defaulted to 23.2 but a warning about vendored Pip 20.3.4 was issued
anyway; this is now fixed. For both Python 3.11 and Python 3.12, the
vendored version of packaging used the deprecated `sre_constants`
stdlib module; this is now fixed with packaging 23.1 being vendored
and selected for Python >= 3.7.

Fixes #2186

pex/bin/pex.py

@@ -38,7 +38,7 @@
 from pex.resolve.configured_resolve import resolve
 from pex.resolve.requirement_configuration import RequirementConfiguration
 from pex.resolve.resolvers import Unsatisfiable
-from pex.result import catch
+from pex.result import ResultError, catch, try_
 from pex.targets import Targets
 from pex.tracer import TRACER
 from pex.typing import TYPE_CHECKING, cast
@@ -886,8 +886,8 @@ def main(args=None):
             except target_configuration.InterpreterConstraintsNotSatisfied as e:
                 die(str(e), exit_code=CANNOT_SETUP_INTERPRETER)
 
-            resolver_configuration = finalize_resolve_config(
-                resolver_configuration, targets, context="PEX building"
+            resolver_configuration = try_(
+                finalize_resolve_config(resolver_configuration, targets, context="PEX building")
             )
 
             sys.exit(
@@ -902,7 +902,7 @@ def main(args=None):
                     env=env,
                 )
             )
-    except GlobalConfigurationError as e:
+    except (GlobalConfigurationError, ResultError) as e:
         die(str(e))
 
 

pex/pip/installation.py

@@ -123,6 +123,7 @@ def _resolved_installation(
             targets,
             PipVersion.VENDORED,
             context="Bootstrapping Pip {version}".format(version=version),
+            warn=False,
         )
     )
     if bootstrap_pip_version is not PipVersion.VENDORED:
@@ -217,6 +218,7 @@ def compatible_version(
     targets,  # type: Targets
     requested_version,  # type: PipVersionValue
     context,  # type: str
+    warn=True,  # type: bool
 ):
     # type: (...) -> Union[PipVersionValue, Error]
     try:
@@ -228,9 +230,10 @@ def compatible_version(
         for version in remaining_versions:
             try:
                 validate_targets(targets, version, context)
-                pex_warnings.warn(
-                    "{err}\n" "\n" "Using Pip {version} instead.".format(err=e, version=version)
-                )
+                if warn:
+                    pex_warnings.warn(
+                        "{err}\n" "\n" "Using Pip {version} instead.".format(err=e, version=version)
+                    )
                 return version
             except RequiresPythonError:
                 continue

pex/vendor/__init__.py

@@ -180,12 +180,14 @@ def iter_vendor_specs(filter_requires_python=False):
         yield VendorSpec.pinned(
             "packaging", "20.9", import_path="packaging_20_9", constraints=("pyparsing<3",)
         )
-    if not filter_requires_python or sys.version_info[:2] >= (3, 6):
+    if not filter_requires_python or sys.version_info[:2] == (3, 6):
         # N.B.: The pyparsing constraint is needed because our import re-writer (RedBaron) chokes on
         # newer versions.
         yield VendorSpec.pinned(
             "packaging", "21.3", import_path="packaging_21_3", constraints=("pyparsing<3",)
         )
+    if not filter_requires_python or sys.version_info[:2] >= (3, 7):
+        yield VendorSpec.pinned("packaging", "23.1", import_path="packaging_23_1")
 
     # We use toml to read pyproject.toml when building sdists from local source projects.
     yield VendorSpec.pinned("toml", "0.10.2")

scripts/package.py

@@ -59,7 +59,7 @@ def build_pex_pex(output_file: PurePath, verbosity: int = 0) -> None:
 
 def describe_git_rev() -> str:
     git_describe = subprocess.run(
-        ["git", "describe"], check=True, capture_output=True, encoding="utf-8"
+        ["git", "describe"], check=True, stdout=subprocess.PIPE, encoding="utf-8"
     )
     return git_describe.stdout.strip()
 

tests/integration/test_issue_2186.py

@@ -0,0 +1,78 @@
+# Copyright 2023 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+from textwrap import dedent
+from typing import NoReturn, Union
+
+import pytest
+
+from pex import targets
+from pex.interpreter import PythonInterpreter
+from pex.pip.version import PipVersion, PipVersionValue
+from pex.testing import IntegResults, run_pex_command
+
+
+def pex_execute_cowsay(*extra_pex_args):
+    # type: (*str) -> IntegResults
+    return run_pex_command(
+        args=list(extra_pex_args) + ["cowsay==5.0", "-c", "cowsay", "--", "Moo!"], quiet=True
+    )
+
+
+def test_default_resolve_no_warning():
+    # type: () -> None
+
+    result = pex_execute_cowsay()
+    result.assert_success()
+    assert not result.error
+    assert "Moo!" in result.output
+
+
+@pytest.fixture
+def incompatible_pip_version():
+    # type: () -> Union[PipVersionValue, NoReturn]
+    for pip_version in PipVersion.values():
+        if not pip_version.requires_python_applies(targets.current()):
+            return pip_version
+
+    pytest.skip(
+        "There is no supported Pip version incompatible with {interpreter}.".format(
+            interpreter=PythonInterpreter.get()
+        )
+    )
+    raise AssertionError("Unreachable: satisfy type checker.")
+
+
+def expected_incompatible_pip_message(incompatible_pip_version):
+    # type: (PipVersionValue) -> str
+    return dedent(
+        """\
+        Pip {pip_version} requires Python {python_req} and the following target does not apply:
+        1. {target}
+        """.format(
+            pip_version=incompatible_pip_version,
+            python_req=incompatible_pip_version.requires_python,
+            target=targets.current(),
+        )
+    )
+
+
+def test_incompatible_resolve_warning(incompatible_pip_version):
+    # type: (PipVersionValue) -> None
+
+    result = pex_execute_cowsay("--pip-version", str(incompatible_pip_version))
+    result.assert_success()
+    assert expected_incompatible_pip_message(incompatible_pip_version) in result.error, result.error
+    assert "Moo!" in result.output, result.output
+
+
+def test_incompatible_resolve_error(incompatible_pip_version):
+    # type: (PipVersionValue) -> None
+
+    result = pex_execute_cowsay(
+        "--pip-version", str(incompatible_pip_version), "--no-allow-pip-version-fallback"
+    )
+    result.assert_failure()
+    assert result.error.endswith(
+        expected_incompatible_pip_message(incompatible_pip_version)
+    ), result.error

tox.ini

@@ -34,7 +34,8 @@ deps =
     # Python < 3.6 in newer releases so we force low here.
     more-itertools<=8.10.0; python_version < "3.6"
     pytest==4.6.11; python_version < "3.6"
-    pytest==6.2.5; python_version >= "3.6"
+    pytest==6.2.5; python_version == "3.6"
+    pytest==7.4.0; python_version >= "3.7"
     pkginfo==1.7.0
     py{27,py27}: mock==3.0.5
     subprocess: subprocess32