stability improvements

- provide full traceback when a model fails to load
- fix VAE record for VoxelArt; otherwise load fails

configs/INITIAL_MODELS.yaml

@@ -93,6 +93,7 @@ voxel_art-1.0:
    format: ckpt
    vae:
      repo_id: stabilityai/sd-vae-ft-mse
+     file: vae-ft-mse-840000-ema-pruned.ckpt
    recommended: False
    width: 512
    height: 512
@@ -102,7 +103,7 @@ ft-mse-improved-autoencoder-840000:
    format: ckpt
    config: VAE/default
    file: vae-ft-mse-840000-ema-pruned.ckpt
-   recommended: False
+   recommended: True
    width: 512
    height: 512
 trinart_vae:

ldm/generate.py

@@ -844,6 +844,7 @@ class Generate:
             model_data = cache.get_model(model_name)
         except Exception as e:
             print(f'** model {model_name} could not be loaded: {str(e)}')
+            print(traceback.format_exc(), file=sys.stderr)
             if previous_model_name is None:
                 raise e
             print(f'** trying to reload previous model')