Add comprehensive OpenMP fork() prevention

- Set extensive environment variables in both gradio_app.py and rembg.py
- Added KMP_INIT_AT_FORK=FALSE to prevent OpenMP initialization at fork
- Added OMP_WAIT_POLICY=PASSIVE for better thread management
- Added TOKENIZERS_PARALLELISM=false to prevent tokenizer conflicts
- Enhanced error detection for OpenMP fork() errors in rembg library
- Provides clear diagnostic messages when rembg internal processes fail

gradio_app.py

@@ -1,15 +1,20 @@
-# Set OpenMP environment variables to prevent fork() errors
+# Set comprehensive OpenMP environment variables to prevent ANY fork() errors
+# This must be done BEFORE importing any libraries that use OpenMP (torch, numpy, rembg, etc.)
 import os
 os.environ["OMP_NUM_THREADS"] = "1"  # Limit OpenMP to single thread
-os.environ["PYTHONFAULTHANDLER"] = "1"  # Better error reporting
-os.environ["KMP_DUPLICATE_LIB_OK"] = "TRUE"  # Avoid Intel MKL errors
-os.environ["OMP_THREAD_LIMIT"] = "1"  # Limit total number of OpenMP threads
 os.environ["MKL_NUM_THREADS"] = "1"  # Intel MKL threading
 os.environ["NUMEXPR_NUM_THREADS"] = "1"  # NumExpr threading
 os.environ["OPENBLAS_NUM_THREADS"] = "1"  # OpenBLAS threading
 os.environ["VECLIB_MAXIMUM_THREADS"] = "1"  # Apple vecLib threading
+os.environ["KMP_DUPLICATE_LIB_OK"] = "TRUE"  # Avoid Intel MKL errors
+os.environ["OMP_THREAD_LIMIT"] = "1"  # Limit total number of OpenMP threads
 os.environ["OMP_DISPLAY_ENV"] = "FALSE"  # Suppress OpenMP environment display
 os.environ["KMP_WARNINGS"] = "FALSE"  # Suppress KMP warnings
+os.environ["PYTHONFAULTHANDLER"] = "1"  # Better error reporting
+# Additional settings to prevent subprocess/multiprocessing issues in rembg and other libraries
+os.environ["TOKENIZERS_PARALLELISM"] = "false"  # Disable tokenizer parallelism
+os.environ["OMP_WAIT_POLICY"] = "PASSIVE"  # Use passive waiting
+os.environ["KMP_INIT_AT_FORK"] = "FALSE"  # Don't initialize OpenMP at fork
 
 # Hunyuan 3D is licensed under the TENCENT HUNYUAN NON-COMMERCIAL LICENSE AGREEMENT
 # except for the third-party components listed below.

hy3dshape/hy3dshape/rembg.py

@@ -17,12 +17,22 @@ import io
 import traceback
 import numpy as np
 
-# Set OpenMP environment variables to prevent threading conflicts
-# This allows rembg to run safely in the main thread without multiprocessing
+# Set comprehensive OpenMP environment variables to prevent ANY threading/fork conflicts
+# This prevents both our code and the rembg library from causing OpenMP fork() errors
 os.environ["OMP_NUM_THREADS"] = "1"  # Limit OpenMP to single thread
-os.environ["PYTHONFAULTHANDLER"] = "1"  # Better error reporting
+os.environ["MKL_NUM_THREADS"] = "1"  # Intel MKL threading
+os.environ["NUMEXPR_NUM_THREADS"] = "1"  # NumExpr threading
+os.environ["OPENBLAS_NUM_THREADS"] = "1"  # OpenBLAS threading
+os.environ["VECLIB_MAXIMUM_THREADS"] = "1"  # Apple Accelerate threading
 os.environ["KMP_DUPLICATE_LIB_OK"] = "TRUE"  # Avoid Intel MKL errors
 os.environ["OMP_THREAD_LIMIT"] = "1"  # Limit total number of OpenMP threads
+os.environ["OMP_DISPLAY_ENV"] = "FALSE"  # Don't display OpenMP environment
+os.environ["KMP_WARNINGS"] = "FALSE"  # Suppress KMP warnings
+os.environ["PYTHONFAULTHANDLER"] = "1"  # Better error reporting
+# Additional settings to prevent subprocess/multiprocessing issues in rembg
+os.environ["TOKENIZERS_PARALLELISM"] = "false"  # Disable tokenizer parallelism
+os.environ["OMP_WAIT_POLICY"] = "PASSIVE"  # Use passive waiting
+os.environ["KMP_INIT_AT_FORK"] = "FALSE"  # Don't initialize OpenMP at fork
 
 from PIL import Image
 from rembg import remove, new_session
@@ -113,9 +123,17 @@ class BackgroundRemover():
                 print("Alpha matting successful!")
                 return output
             except Exception as e:
+                error_msg = str(e)
                 print(f"Alpha matting failed: {e}")
-                import traceback
-                traceback.print_exc()
+                
+                # Check for specific OpenMP fork errors
+                if "fork()" in error_msg and "OpenMP" in error_msg:
+                    print("DETECTED: OpenMP fork() error in rembg library itself!")
+                    print("This is an internal rembg issue, not our code.")
+                    print("Falling back to standard background removal...")
+                else:
+                    import traceback
+                    traceback.print_exc()
             
             # If alpha matting fails, try standard background removal
             print("Alpha matting failed, falling back to standard background removal")
@@ -130,9 +148,17 @@ class BackgroundRemover():
                 print("Standard background removal successful!")
                 return output
             except Exception as e:
+                error_msg = str(e)
                 print(f"Standard background removal failed: {e}")
-                import traceback
-                traceback.print_exc()
+                
+                # Check for specific OpenMP fork errors
+                if "fork()" in error_msg and "OpenMP" in error_msg:
+                    print("DETECTED: OpenMP fork() error in rembg library (standard mode)!")
+                    print("The rembg library itself has internal multiprocessing that conflicts with OpenMP.")
+                    print("This is a known issue with the rembg library in daemon environments.")
+                else:
+                    import traceback
+                    traceback.print_exc()
             
             # If all else fails, return the original image
             print("Background removal completely failed, returning original image")