pathfinder: skip nvcudla tests when runtime is absent

Skip the cudla and nvcudla load tests on aarch64 hosts when the nvcudla canary
probe cannot resolve libnvcudla.so. This keeps non-Tegra linux-aarch64 systems
from failing strict test runs while still exercising the real success path on
Tegra platforms where the platform runtime is installed.

Made-with: Cursor

Author: rwgk

cuda_pathfinder/tests/test_driver_lib_loading.py

@@ -16,6 +16,7 @@
     run_load_nvidia_dynamic_lib_in_subprocess,
 )
 
+from cuda.pathfinder._dynamic_libs import load_nvidia_dynamic_lib as load_nvidia_dynamic_lib_module
 from cuda.pathfinder._dynamic_libs.lib_descriptor import LIB_DESCRIPTORS
 from cuda.pathfinder._dynamic_libs.load_dl_common import DynamicLibNotFoundError, LoadedDL
 from cuda.pathfinder._dynamic_libs.load_nvidia_dynamic_lib import (
@@ -24,7 +25,7 @@
     _load_lib_no_cache,
 )
 from cuda.pathfinder._dynamic_libs.subprocess_protocol import STATUS_NOT_FOUND, parse_dynamic_lib_subprocess_payload
-from cuda.pathfinder._utils.platform_aware import IS_WINDOWS, quote_for_shell
+from cuda.pathfinder._utils.platform_aware import IS_WINDOWS, PLATFORM_MACHINE, quote_for_shell
 
 STRICTNESS = os.environ.get("CUDA_PATHFINDER_TEST_LOAD_NVIDIA_DYNAMIC_LIB_STRICTNESS", "see_what_works")
 assert STRICTNESS in ("see_what_works", "all_must_work")
@@ -40,6 +41,14 @@ def _make_loaded_dl(path, found_via):
     return LoadedDL(path, False, 0xDEAD, found_via)
 
 
+def _skip_if_missing_nvcudla_runtime(libname: str, *, timeout: float) -> None:
+    if libname != "nvcudla" or PLATFORM_MACHINE != "aarch64":
+        return
+    if load_nvidia_dynamic_lib_module._loadable_via_canary_subprocess("nvcudla", timeout=timeout):
+        return
+    pytest.skip("libnvcudla.so is not loadable via canary subprocess on this host.")
+
+
 # ---------------------------------------------------------------------------
 # _load_driver_lib_no_cache
 # ---------------------------------------------------------------------------
@@ -147,6 +156,7 @@ def raise_child_process_failed():
         error_label="Load subprocess child process",
     )
     if payload.status == STATUS_NOT_FOUND:
+        _skip_if_missing_nvcudla_runtime(libname, timeout=timeout)
         if STRICTNESS == "all_must_work":
             raise_child_process_failed()
         info_summary_append(f"Not found: {libname=!r}")

cuda_pathfinder/tests/test_load_nvidia_dynamic_lib.py

@@ -18,7 +18,7 @@
     STATUS_NOT_FOUND,
     parse_dynamic_lib_subprocess_payload,
 )
-from cuda.pathfinder._utils.platform_aware import IS_WINDOWS, quote_for_shell
+from cuda.pathfinder._utils.platform_aware import IS_WINDOWS, PLATFORM_MACHINE, quote_for_shell
 
 STRICTNESS = os.environ.get("CUDA_PATHFINDER_TEST_LOAD_NVIDIA_DYNAMIC_LIB_STRICTNESS", "see_what_works")
 assert STRICTNESS in ("see_what_works", "all_must_work")
@@ -106,6 +106,14 @@ def _is_expected_load_nvidia_dynamic_lib_failure(libname):
     return False
 
 
+def _skip_if_missing_nvcudla_runtime(libname: str, *, timeout: float) -> None:
+    if libname != "nvcudla" or PLATFORM_MACHINE != "aarch64":
+        return
+    if load_nvidia_dynamic_lib_module._loadable_via_canary_subprocess("nvcudla", timeout=timeout):
+        return
+    pytest.skip("libnvcudla.so is not loadable via canary subprocess on this host.")
+
+
 @pytest.mark.parametrize(
     "libname",
     supported_nvidia_libs.SUPPORTED_WINDOWS_DLLS if IS_WINDOWS else supported_nvidia_libs.SUPPORTED_LINUX_SONAMES,
@@ -132,6 +140,7 @@ def raise_child_process_failed():
         error_label="Load subprocess child process",
     )
     if payload.status == STATUS_NOT_FOUND:
+        _skip_if_missing_nvcudla_runtime(libname, timeout=timeout)
         if STRICTNESS == "all_must_work" and not _is_expected_load_nvidia_dynamic_lib_failure(libname):
             raise_child_process_failed()
         info_summary_append(f"Not found: {libname=!r}")