Temp fix for broken detectron2 import (#18699)

* add first generation tutorial

* [Circle CI] Temporary fix for broken detectron2 import

* remove generation

src/transformers/models/layoutlmv2/modeling_layoutlmv2.py

@@ -43,12 +43,26 @@ from ...utils import (
 from .configuration_layoutlmv2 import LayoutLMv2Config
 
 
+logger = logging.get_logger(__name__)
+
+
 # soft dependency
 if is_detectron2_available():
     import detectron2
-    from detectron2.modeling import META_ARCH_REGISTRY
 
-logger = logging.get_logger(__name__)
+    try:
+        from detectron2.modeling import META_ARCH_REGISTRY
+    except ImportError:
+        # NOTE: This is a temporary fix because currently there are
+        # import problems when using detectron2 from master (see issues below)
+        # it's better to have a silent error here in case someone imports this file
+        # without using the model which without this hack would break.
+        logger.warning(
+            "The detectron2 import seems to be broken. See:"
+            "https://github.com/facebookresearch/detectron2/issues/4489 or"
+            "https://github.com/facebookresearch/detectron2/issues/4487"
+        )
+        pass
 
 _CHECKPOINT_FOR_DOC = "microsoft/layoutlmv2-base-uncased"
 _CONFIG_FOR_DOC = "LayoutLMv2Config"