correct env var usage

Author: vlad-scherbich

ddtrace/internal/settings/profiling.py

@@ -75,9 +75,8 @@ def _check_for_stack_available() -> tuple[str, bool]:
 
 
 def _check_for_native_heap_available() -> tuple[str, bool]:
-    # Importing heap_gotter dlopen's the gotter cdylib (if present) but does
-    # NOT install anything; installation is an explicit, separate call.
-    # The module is fail-closed and never raises on import.
+    # Importing heap_gotter dlopen's the gotter cdylib but does NOT install
+    # anything; installation is an explicit, separate call. Import never raises.
     from ddtrace.internal.datadog.profiling import heap_gotter
 
     return (heap_gotter.failure_msg, heap_gotter.is_available)
@@ -694,9 +693,9 @@ def _check_for_exception_available() -> tuple[str, bool]:
 if not exception_is_available and config.exception.enabled:
     config.exception.enabled = False  # pyright: ignore[reportAttributeAccessIssue]
 
-# Native heap profiling only arms USDT probes via a separately-built cdylib.
+# Native heap profiling only arms USDT probes via the gotter cdylib.
 # Check availability lazily (only when requested) so the common disabled path
-# never dlopen's the gotter library, and fail closed if it can't be loaded.
+# never dlopen's the gotter library. Disable the feature if it can't be loaded.
 if config.native_heap.enabled:
     native_heap_failure_msg, native_heap_is_available = _check_for_native_heap_available()
     if not native_heap_is_available:

tests/profiling/test_native_heap_gotter.py

@@ -1,13 +1,7 @@
 """Smoke tests for the native (C/C++) heap profiling activator.
 
-The activator (``ddtrace.internal.datadog.profiling.heap_gotter``) is fail-closed
-and must behave correctly whether or not the opt-in gotter cdylib was built into
-the wheel (``DD_PROFILING_NATIVE_HEAP_ENABLED=1`` at build time):
-
-* If the library is absent (the default), ``install()``/``is_installed()`` are
-  no-ops returning ``False``.
-* If present (a native-heap build on Linux), ``install()`` patches the process
-  GOT and ``is_installed()`` flips to ``True`` and stays there (idempotent).
+``install()`` patches the process GOT and ``is_installed()`` flips to ``True``
+and stays there (idempotent).
 
 Proving that the ``ddheap`` USDT probes actually *fire* requires attaching the
 Full Host eBPF profiler (or a ``test-support`` build exposing the hook-hit
@@ -50,15 +44,14 @@ def test_native_heap_gotter_fork_install_and_allocations() -> None:
     """dlopen + install, then fork and keep allocating in parent and child.
 
     Exercises the gunicorn/uWSGI-shaped path where the activator may run before
-    fork and again in the child. When the cdylib is present, GOT overrides are
-    inherited; when absent, install() stays a no-op. Either way, fork + alloc
-    must not crash.
+    fork and again in the child. GOT overrides are inherited across fork;
+    fork + alloc must not crash.
     """
     import os
 
     from ddtrace.internal.datadog.profiling import heap_gotter
 
-    # Import already dlopen'd (or fail-closed). Arm in the parent.
+    # Import already dlopen'd. Arm in the parent.
     armed = heap_gotter.install()
     if heap_gotter.is_available:
         assert armed is True

tests/profiling/test_profiling_config.py

@@ -237,20 +237,13 @@ def test_config_str_omits_tag_when_disabled(self, monkeypatch: pytest.MonkeyPatc
 
 
 class TestNativeHeapActivator:
-    """The ctypes activator must load fail-closed and never raise, regardless of
-    platform or whether the gotter cdylib was built into the wheel.
-    """
+    """The ctypes activator must not raise on import."""
 
-    def test_import_is_fail_closed(self) -> None:
+    def test_import_does_not_raise(self) -> None:
         from ddtrace.internal.datadog.profiling import heap_gotter
 
         assert isinstance(heap_gotter.is_available, bool)
         assert isinstance(heap_gotter.failure_msg, str)
-        # When the library is absent/unsupported, entry points are no-ops that
-        # return False and do not rewrite GOT — safe to call in-process.
-        # When available, do not call install() here: GOT patching is permanent
-        # and would poison the shared pytest worker. That path is covered by the
-        # subprocess smoke/fork tests in test_native_heap_gotter.py.
-        if not heap_gotter.is_available:
-            assert heap_gotter.install() is False
-            assert heap_gotter.is_installed() is False
+        # Do not call install() here: GOT patching is permanent and would poison
+        # the shared pytest worker. That path is covered by the subprocess
+        # smoke/fork tests in test_native_heap_gotter.py.