Enhance Zero GPU support with environment variable control and improved error handling

app.py

@@ -18,13 +18,28 @@ import shutil
 import uuid
 import gc
 
+# Check if Zero GPU should be disabled via environment variable
+DISABLE_ZERO_GPU = os.environ.get('DISABLE_ZERO_GPU', 'false').lower() == 'true'
+
 # Try to import spaces for Zero GPU support
-try:
-    import spaces
-    SPACES_AVAILABLE = True
-except ImportError:
+if DISABLE_ZERO_GPU:
     SPACES_AVAILABLE = False
-    print("Warning: spaces module not available. Running without Zero GPU support.")
+    print("Zero GPU disabled via environment variable")
+else:
+    try:
+        import spaces
+        SPACES_AVAILABLE = True
+        # Check if we're actually running on Hugging Face Spaces with Zero GPU
+        if hasattr(spaces, 'config') and hasattr(spaces.config, 'Config'):
+            print("Zero GPU support detected and available")
+        else:
+            print("Spaces module imported but Zero GPU may not be fully configured")
+    except ImportError:
+        SPACES_AVAILABLE = False
+        print("Warning: spaces module not available. Running without Zero GPU support.")
+    except Exception as e:
+        SPACES_AVAILABLE = False
+        print(f"Warning: Error importing spaces module: {e}. Running without Zero GPU support.")
 
 # Add current directory to path
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
@@ -341,7 +356,18 @@ def score_and_create_matrix_all_singles_impl(sequence,mutation_range_start=None,
 
 # Apply Zero GPU decorator if available
 if SPACES_AVAILABLE:
-    score_and_create_matrix_all_singles = spaces.GPU(duration=300)(score_and_create_matrix_all_singles_impl)
+    try:
+        # Try with explicit duration
+        score_and_create_matrix_all_singles = spaces.GPU(duration=300)(score_and_create_matrix_all_singles_impl)
+    except Exception as e:
+        print(f"Warning: Failed to apply Zero GPU decorator with duration: {e}")
+        try:
+            # Try without duration parameter
+            score_and_create_matrix_all_singles = spaces.GPU()(score_and_create_matrix_all_singles_impl)
+        except Exception as e2:
+            print(f"Warning: Failed to apply Zero GPU decorator: {e2}")
+            print("Falling back to CPU mode")
+            score_and_create_matrix_all_singles = score_and_create_matrix_all_singles_impl
 else:
     score_and_create_matrix_all_singles = score_and_create_matrix_all_singles_impl