stop swallowing warnings from Pex by default

src/python/pants/backend/python/goals/lockfile.py

@@ -18,7 +18,8 @@
 from pants.backend.python.util_rules.interpreter_constraints import InterpreterConstraints
 from pants.backend.python.util_rules.lockfile_diff import _generate_python_lockfile_diff
 from pants.backend.python.util_rules.lockfile_metadata import PythonLockfileMetadata
-from pants.backend.python.util_rules.pex_cli import PexCliProcess
+from pants.backend.python.util_rules.pex_cli import PexCliProcess, maybe_log_pex_stderr
+from pants.backend.python.util_rules.pex_environment import PexSubsystem
 from pants.backend.python.util_rules.pex_requirements import (
     PexRequirements,
     ResolvePexConfig,
@@ -103,6 +104,7 @@ async def generate_lockfile(
     req: GeneratePythonLockfile,
     generate_lockfiles_subsystem: GenerateLockfilesSubsystem,
     python_setup: PythonSetup,
+    pex_subsystem: PexSubsystem,
 ) -> GenerateLockfileResult:
     pip_args_setup = await _setup_pip_args_and_constraints_file(req.resolve_name)
 
@@ -113,7 +115,6 @@ async def generate_lockfile(
             subcommand=("lock", "create"),
             extra_args=(
                 "--output=lock.json",
-                "--no-emit-warnings",
                 # See https://github.com/pantsbuild/pants/issues/12458. For now, we always
                 # generate universal locks because they have the best compatibility. We may
                 # want to let users change this, as `style=strict` is safer.
@@ -158,6 +159,8 @@ async def generate_lockfile(
         ),
     )
 
+    maybe_log_pex_stderr(result.stderr, pex_subsystem.verbosity)
+
     initial_lockfile_digest_contents = await Get(DigestContents, Digest, result.output_digest)
     metadata = PythonLockfileMetadata.new(
         valid_for_interpreter_constraints=req.interpreter_constraints,

src/python/pants/backend/python/target_types.py

@@ -26,6 +26,7 @@
 
 from pants.backend.python.macros.python_artifact import PythonArtifact
 from pants.backend.python.subsystems.setup import PythonSetup
+from pants.base.deprecated import warn_or_error
 from pants.core.goals.generate_lockfiles import UnrecognizedResolveNamesError
 from pants.core.goals.package import OutputPathField
 from pants.core.goals.run import RestartableField
@@ -381,6 +382,24 @@ class PexArgsField(StringSequenceField):
     )
 
 
+class PexCheckField(StringField):
+    alias = "check"
+    valid_choices = ("none", "warn", "error")
+    expected_type = str
+    default = "error"
+    help = help_text(
+        """
+        Check that the built PEX is valid. Currently this only
+        applies to `--layout zipapp` where the PEX zip is
+        tested for importability of its `__main__` module by
+        the Python zipimport module. This check will fail for
+        PEX zips that use ZIP64 extensions since the Python
+        zipimport zipimporter only works with 32 bit zips. The
+        check no-ops for all other layouts.
+        """
+    )
+
+
 class PexEnvField(DictStringToStringField):
     alias = "env"
     help = help_text(
@@ -545,6 +564,19 @@ class PexEmitWarningsField(TriBoolField):
     def value_or_global_default(self, pex_binary_defaults: PexBinaryDefaults) -> bool:
         if self.value is None:
             return pex_binary_defaults.emit_warnings
+        warn_or_error(
+            "2.21.0.dev0",
+            softwrap(
+                """
+                          `emit_warnings` no longer set per target.
+                          Use `emit_warnings` on the [pex] subsytem to control warnings for
+                          all pex invocations
+                          """
+            ),
+            "use [pex] subsystem instead",
+            start_version="2.20.0.dev0",
+        )
+
         return self.value
 
 
@@ -697,6 +729,7 @@ class PexVenvHermeticScripts(BoolField):
     InterpreterConstraintsField,
     PythonResolveField,
     PexBinaryDependenciesField,
+    PexCheckField,
     PexPlatformsField,
     PexCompletePlatformsField,
     PexResolveLocalPlatformsField,
@@ -837,6 +870,8 @@ class PexBinaryDefaults(Subsystem):
             `pex_binary` targets
             """
         ),
+        removal_version="2.21.0.dev0",
+        removal_hint="Use the [pex] subsystem to control warnings for all Pex invocations",
         advanced=True,
     )
     resolve_local_platforms = BoolOption(

src/python/pants/backend/python/util_rules/pex.py

@@ -30,7 +30,7 @@
 )
 from pants.backend.python.util_rules import pex_cli, pex_requirements
 from pants.backend.python.util_rules.interpreter_constraints import InterpreterConstraints
-from pants.backend.python.util_rules.pex_cli import PexCliProcess, PexPEX
+from pants.backend.python.util_rules.pex_cli import PexCliProcess, PexPEX, maybe_log_pex_stderr
 from pants.backend.python.util_rules.pex_environment import (
     CompletePexEnvironment,
     PexEnvironment,
@@ -400,10 +400,7 @@ async def find_interpreter(
     )
     path, fingerprint = result.stdout.decode().strip().splitlines()
 
-    if pex_subsystem.verbosity > 0:
-        log_output = result.stderr.decode()
-        if log_output:
-            logger.info("%s", log_output)
+    maybe_log_pex_stderr(result.stderr, pex_subsystem.verbosity)
 
     return PythonExecutable(path=path, fingerprint=fingerprint)
 
@@ -675,7 +672,6 @@ async def build_pex(
     argv = [
         "--output-file",
         request.output_filename,
-        "--no-emit-warnings",
         *request.additional_args,
     ]
 
@@ -746,10 +742,7 @@ async def build_pex(
         ),
     )
 
-    if pex_subsystem.verbosity > 0:
-        log_output = result.stderr.decode()
-        if log_output:
-            logger.info("%s", log_output)
+    maybe_log_pex_stderr(result.stderr, pex_subsystem.verbosity)
 
     digest = (
         await Get(

src/python/pants/backend/python/util_rules/pex_cli.py

@@ -4,6 +4,7 @@
 from __future__ import annotations
 
 import dataclasses
+import logging
 import os.path
 from dataclasses import dataclass
 from typing import Iterable, List, Mapping, Optional, Tuple
@@ -29,6 +30,8 @@
 from pants.util.logging import LogLevel
 from pants.util.meta import classproperty
 
+logger = logging.getLogger(__name__)
+
 
 class PexCli(TemplatedExternalTool):
     options_scope = "pex-cli"
@@ -156,6 +159,8 @@ async def setup_pex_cli_process(
 
     verbosity_args = [f"-{'v' * pex_subsystem.verbosity}"] if pex_subsystem.verbosity > 0 else []
 
+    warnings_args = [] if pex_subsystem.emit_warnings else ["--no-emit-warnings"]
+
     # NB: We should always pass `--python-path`, as that tells Pex where to look for interpreters
     # when `--python` isn't an absolute path.
     resolve_args = [
@@ -171,6 +176,7 @@ async def setup_pex_cli_process(
         *request.subcommand,
         *global_args,
         *verbosity_args,
+        *warnings_args,
         *pip_version_args,
         *resolve_args,
         # NB: This comes at the end because it may use `--` passthrough args, # which must come at
@@ -202,6 +208,15 @@ async def setup_pex_cli_process(
     )
 
 
+def maybe_log_pex_stderr(stderr: bytes, pex_verbosity: int) -> None:
+    """Forward Pex's stderr to a Pants logger if conditions are met."""
+    log_output = stderr.decode()
+    if log_output and pex_verbosity > 0:
+        logger.info("%s", log_output)
+    elif log_output and "PEXWarning:" in log_output:
+        logger.warning("%s", log_output)
+
+
 def rules():
     return [
         *collect_rules(),

src/python/pants/backend/python/util_rules/pex_environment.py

@@ -81,6 +81,14 @@ def iter_path_entries():
         ),
         advanced=True,
     )
+    emit_warnings = BoolOption(
+        default=True,
+        help=softwrap(
+            """
+            If warnings from Pex should be logged by Pants to the console.
+            """
+        ),
+    )
 
     @property
     def verbosity(self) -> int: