Sanity check: Add check for lib being None

bitsandbytes/diagnostics/main.py

@@ -13,6 +13,21 @@
 
 
 def sanity_check():
+ from bitsandbytes.cextension import lib
+
+ if lib is None:
+ print_dedented(
+ """
+ Couldn't load the bitsandbytes library, likely due to missing binaries.
+ Please ensure bitsandbytes is properly installed.
+
+ For source installations, compile the binaries with `cmake -DCOMPUTE_BACKEND=cuda -S .`.
+ See the documentation for more details if needed.
+
+ Trying a simple check anyway, but this will likely fail...
+ """
+ )
+
  from bitsandbytes.optim import Adam
 
  p = torch.nn.Parameter(torch.rand(10, 10).cuda())