Remove PANTS(C)_PROFILE in favor of recommending py-spy. (pantsbu…

…ild#16226)

`py-spy` is superior to `cProfile` based profiling, and is already [documented](https://github.com/pantsbuild/pants/blob/99e2130deec1ad87a417cdc997a5fecd3f458965/docs/markdown/Contributions/development/contributions-debugging.md#profiling-with-py-spy). Remove the `PANTS(C)_PROFILE` environment variables which used to trigger profiling (which are _not_ documented).

Fixes pantsbuild#3431.

[ci skip-rust]
[ci skip-build-wheels]

src/python/pants/bin/local_pants_runner.py

@@ -31,7 +31,6 @@
 from pants.option.global_options import DynamicRemoteOptions, DynamicUIRenderer
 from pants.option.options import Options
 from pants.option.options_bootstrapper import OptionsBootstrapper
-from pants.util.contextutil import maybe_profiled
 from pants.util.logging import LogLevel
 
 logger = logging.getLogger(__name__)
@@ -46,7 +45,6 @@ class LocalPantsRunner:
     run_tracker: A tracker for metrics for the run.
     specs: The specs for this run, i.e. either the address or filesystem specs.
     graph_session: A LegacyGraphSession instance for graph reuse.
-    profile_path: The profile path - if any (from from the `PANTS_PROFILE` env var).
     """
 
     options: Options
@@ -56,7 +54,6 @@ class LocalPantsRunner:
     specs: Specs
     graph_session: GraphSession
     union_membership: UnionMembership
-    profile_path: str | None
 
     @classmethod
     def _init_graph_session(
@@ -162,8 +159,6 @@ def create(
             session=graph_session.scheduler_session,
         )
 
-        profile_path = env.get("PANTS_PROFILE")
-
         return cls(
             options=options,
             options_bootstrapper=options_bootstrapper,
@@ -172,7 +167,6 @@ def create(
             specs=specs,
             graph_session=graph_session,
             union_membership=union_membership,
-            profile_path=profile_path,
         )
 
     def _perform_run(self, goals: tuple[str, ...]) -> ExitCode:
@@ -246,35 +240,34 @@ def _run_inner(self) -> ExitCode:
             return PANTS_FAILED_EXIT_CODE
 
     def run(self, start_time: float) -> ExitCode:
-        with maybe_profiled(self.profile_path):
-            spec_parser = SpecsParser()
-            specs = []
-            for spec_str in self.options.specs:
-                spec, is_ignore = spec_parser.parse_spec(spec_str)
-                specs.append(f"-{spec}" if is_ignore else str(spec))
-
-            self.run_tracker.start(run_start_time=start_time, specs=specs)
-            global_options = self.options.for_global_scope()
-
-            streaming_reporter = StreamingWorkunitHandler(
-                self.graph_session.scheduler_session,
-                run_tracker=self.run_tracker,
-                specs=self.specs,
-                options_bootstrapper=self.options_bootstrapper,
-                callbacks=self._get_workunits_callbacks(),
-                report_interval_seconds=global_options.streaming_workunits_report_interval,
-                allow_async_completion=(
-                    global_options.pantsd and global_options.streaming_workunits_complete_async
-                ),
-                max_workunit_verbosity=global_options.streaming_workunits_level,
-            )
-            with streaming_reporter:
-                engine_result = PANTS_FAILED_EXIT_CODE
-                try:
-                    engine_result = self._run_inner()
-                finally:
-                    metrics = self.graph_session.scheduler_session.metrics()
-                    self.run_tracker.set_pantsd_scheduler_metrics(metrics)
-                    self.run_tracker.end_run(engine_result)
-
-                return engine_result
+        spec_parser = SpecsParser()
+        specs = []
+        for spec_str in self.options.specs:
+            spec, is_ignore = spec_parser.parse_spec(spec_str)
+            specs.append(f"-{spec}" if is_ignore else str(spec))
+
+        self.run_tracker.start(run_start_time=start_time, specs=specs)
+        global_options = self.options.for_global_scope()
+
+        streaming_reporter = StreamingWorkunitHandler(
+            self.graph_session.scheduler_session,
+            run_tracker=self.run_tracker,
+            specs=self.specs,
+            options_bootstrapper=self.options_bootstrapper,
+            callbacks=self._get_workunits_callbacks(),
+            report_interval_seconds=global_options.streaming_workunits_report_interval,
+            allow_async_completion=(
+                global_options.pantsd and global_options.streaming_workunits_complete_async
+            ),
+            max_workunit_verbosity=global_options.streaming_workunits_level,
+        )
+        with streaming_reporter:
+            engine_result = PANTS_FAILED_EXIT_CODE
+            try:
+                engine_result = self._run_inner()
+            finally:
+                metrics = self.graph_session.scheduler_session.metrics()
+                self.run_tracker.set_pantsd_scheduler_metrics(metrics)
+                self.run_tracker.end_run(engine_result)
+
+            return engine_result

src/python/pants/bin/pants_env_vars.py

@@ -5,4 +5,3 @@
 IGNORE_UNRECOGNIZED_ENCODING = "PANTS_IGNORE_UNRECOGNIZED_ENCODING"
 RECURSION_LIMIT = "PANTS_RECURSION_LIMIT"
 DAEMON_ENTRYPOINT = "PANTS_DAEMON_ENTRYPOINT"
-PANTSC_PROFILE = "PANTSC_PROFILE"

src/python/pants/bin/pants_loader.py

@@ -13,11 +13,9 @@
 from pants.bin.pants_env_vars import (
     DAEMON_ENTRYPOINT,
     IGNORE_UNRECOGNIZED_ENCODING,
-    PANTSC_PROFILE,
     RECURSION_LIMIT,
 )
 from pants.bin.pants_runner import PantsRunner
-from pants.util.contextutil import maybe_profiled
 
 
 class PantsLoader:
@@ -86,14 +84,13 @@ def run_alternate_entrypoint(entrypoint: str) -> None:
 
     @staticmethod
     def run_default_entrypoint() -> None:
-        with maybe_profiled(os.environ.get(PANTSC_PROFILE)):
-            start_time = time.time()
-            try:
-                runner = PantsRunner(args=sys.argv, env=os.environ)
-                exit_code = runner.run(start_time)
-            except KeyboardInterrupt as e:
-                print(f"Interrupted by user:\n{e}", file=sys.stderr)
-                exit_code = PANTS_FAILED_EXIT_CODE
+        start_time = time.time()
+        try:
+            runner = PantsRunner(args=sys.argv, env=os.environ)
+            exit_code = runner.run(start_time)
+        except KeyboardInterrupt as e:
+            print(f"Interrupted by user:\n{e}", file=sys.stderr)
+            exit_code = PANTS_FAILED_EXIT_CODE
         sys.exit(exit_code)
 
     @classmethod

src/python/pants/testutil/pants_integration_test.py

@@ -136,7 +136,6 @@ def run_pants_with_workdir_without_waiting(
         for h in (
             "HOME",
             "PATH",  # Needed to find Python interpreters and other binaries.
-            "PANTS_PROFILE",
         ):
             value = os.getenv(h)
             if value is not None:

src/python/pants/util/contextutil.py

@@ -3,7 +3,6 @@
 
 from __future__ import annotations
 
-import logging
 import os
 import shutil
 import ssl
@@ -17,8 +16,6 @@
 from socketserver import TCPServer
 from typing import IO, Any, Callable, Iterator, Mapping
 
-from colors import green
-
 from pants.util.dirutil import safe_delete
 
 
@@ -247,35 +244,6 @@ def open_zip(path_or_file: str | Any, *args, **kwargs) -> Iterator[zipfile.ZipFi
         zf.close()
 
 
-@contextmanager
-def maybe_profiled(profile_path: str | None) -> Iterator[None]:
-    """A profiling context manager.
-
-    :param profile_path: The path to write profile information to. If `None`, this will no-op.
-    """
-    if not profile_path:
-        yield
-        return
-
-    import cProfile
-
-    profiler = cProfile.Profile()
-    try:
-        profiler.enable()
-        yield
-    finally:
-        profiler.disable()
-        profiler.dump_stats(profile_path)
-        view_cmd = green(
-            "gprof2dot -f pstats {path} | dot -Tpng -o {path}.png && open {path}.png".format(
-                path=profile_path
-            )
-        )
-        logging.getLogger().info(
-            f"Dumped profile data to: {profile_path}\nUse e.g. {view_cmd} to render and view."
-        )
-
-
 @contextmanager
 def http_server(handler_class: type, ssl_context: ssl.SSLContext | None = None) -> Iterator[int]:
     def serve(port_queue: Queue[int], shutdown_queue: Queue[bool]) -> None:

src/python/pants/util/contextutil_test.py

@@ -2,7 +2,6 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 import os
-import pstats
 import shutil
 import subprocess
 import sys
@@ -16,7 +15,6 @@
     InvalidZipPath,
     environment_as,
     hermetic_environment_as,
-    maybe_profiled,
     open_zip,
     pushd,
     temporary_dir,
@@ -199,17 +197,3 @@ def test_permissions(self) -> None:
 
         with temporary_dir(permissions=0o644) as path:
             assert 0o644 == os.stat(path)[0] & 0o777
-
-    def test_maybe_profiled(self) -> None:
-        with temporary_dir() as td:
-            profile_path = os.path.join(td, "profile.prof")
-
-            with maybe_profiled(profile_path):
-                for _ in range(5):
-                    print("test")
-
-            # Ensure the profile data was written.
-            assert os.path.exists(profile_path)
-
-            # Ensure the profile data is valid.
-            pstats.Stats(profile_path).print_stats()