resources fix

Summary: I don't know why RE tests sometimes fail here, but maybe it's a race condition. If that's right, this should fix it.

Reviewed By: shapovalov

Differential Revision: D46020054

fbshipit-source-id: 20b746b09ad9bd77c2601ac681047ccc6cc27ed9

tests/implicitron/common_resources.py

@@ -136,7 +136,10 @@ def _provide_torchvision_weights(par_path: str, filename: str) -> None:
             dest.mkdir(parents=True)
 
         if not (dest / filename).is_symlink():
+            try:
                 (dest / filename).symlink_to(source)
+            except FileExistsError:
+                print("FileExistsError: no symlink created.")
 
 
 def provide_lpips_vgg() -> None: