Fix multi-framework runtime lib loading (#1825)

* Fix single FW build with multi FW available
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

* Some fixes
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

* Fixes
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

* sug
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

---------
Signed-off-by: Kirthi Shankar Sivamani <ksivamani@nvidia.com>

transformer_engine/__init__.py

@@ -11,12 +11,12 @@ import transformer_engine.common
 
 try:
     from . import pytorch
-except ImportError as e:
+except (ImportError, FileNotFoundError):
     pass
 
 try:
     from . import jax
-except ImportError as e:
+except (ImportError, FileNotFoundError):
     pass
 
 __version__ = str(metadata.version("transformer_engine"))

transformer_engine/common/__init__.py

@@ -108,9 +108,10 @@ def _get_shared_object_file(library: str) -> Path:
 
     # Case 1: Typical user workflow: Both locations are the same, return any result.
     if te_install_dir == site_packages_dir:
-        assert (
-            so_path_in_install_dir is not None
-        ), f"Could not find shared object file for Transformer Engine {library} lib."
+        if so_path_in_install_dir is None:
+            raise FileNotFoundError(
+                f"Could not find shared object file for Transformer Engine {library} lib."
+            )
         return so_path_in_install_dir
 
     # Case 2: ERR! Both locations are different but returned a valid result.
@@ -118,8 +119,7 @@ def _get_shared_object_file(library: str) -> Path:
     # editable builds. In case developers are executing inside a TE directory via
     # an inplace build, and then move to a regular build, the local shared object
     # file will be incorrectly picked up without the following logic.
-    if so_path_in_install_dir is not None and so_path_in_default_dir is not None:
-        raise RuntimeError(
+    assert so_path_in_install_dir is None or so_path_in_default_dir is None, (
         f"Found multiple shared object files: {so_path_in_install_dir} and"
         f" {so_path_in_default_dir}. Remove local shared objects installed"
         f" here {so_path_in_install_dir} or change the working directory to"
@@ -134,7 +134,9 @@ def _get_shared_object_file(library: str) -> Path:
     if so_path_in_default_dir is not None:
         return so_path_in_default_dir
 
-    raise RuntimeError(f"Could not find shared object file for Transformer Engine {library} lib.")
+    raise FileNotFoundError(
+        f"Could not find shared object file for Transformer Engine {library} lib."
+    )
 
 
 @functools.lru_cache(maxsize=None)
@@ -198,6 +200,7 @@ def load_framework_extension(framework: str):
 @functools.lru_cache(maxsize=None)
 def _get_sys_extension():
     system = platform.system()
+
     if system == "Linux":
         extension = "so"
     elif system == "Darwin":