feat: Add IIB_SKIP_OPTIONAL_DEPS support and improve error handling for optional packages

- Add environment variable IIB_SKIP_OPTIONAL_DEPS to skip numpy and hnswlib installation
- Provide detailed helpful hints when hnswlib or numpy installation fails
- Include guidance on C++ compiler requirements and pre-built wheel installation
- Add links to related GitHub issues for troubleshooting
- Improve error handling with better Unicode support on Windows
- Skip empty lines and comments in requirements parsing

install.py

@@ -3,6 +3,10 @@ import os
 
 req_file = os.path.join(os.path.dirname(os.path.realpath(__file__)), "requirements.txt")
 
+# Optional dependencies that can be skipped
+OPTIONAL_PACKAGES = {"hnswlib", "numpy"}
+SKIP_OPTIONAL = os.environ.get("IIB_SKIP_OPTIONAL_DEPS", "").lower() in ("1", "true", "yes")
+
 def dist2package(dist: str):
     return ({
         "python-dotenv": "dotenv",
@@ -26,21 +30,57 @@ def extract_package_name(package_spec: str) -> str:
         package_spec = package_spec.split(",")[0].strip()
     return package_spec
 
-
+def get_optional_package_hints(package_name: str) -> str:
+    """Provide helpful hints for optional package installation failures."""
+    hints = {
+        "hnswlib": (
+            "\nNote: hnswlib is optional and only needed for experimental topic clustering/search.\n"
+            "Core image browsing features will still work without hnswlib in some cases.\n"
+            "To skip optional dependencies during installation, set: IIB_SKIP_OPTIONAL_DEPS=1\n"
+            "If you want to install hnswlib, please ensure you have:\n"
+            "  - A C++ compiler (gcc/g++ on Linux, clang on macOS, MSVC on Windows)\n"
+            "  - Python development headers (python3-dev on Ubuntu)\n"
+            "  - Or try: pip install hnswlib --only-binary=:all: for pre-built wheels\n"
+            "See: https://github.com/nmslib/hnswlib/issues/403 and #504 for more details."
+        ),
+        "numpy": (
+            "\nNote: numpy installation failed. Ensure your C++ compiler and Python dev headers are installed.\n"
+            "To skip optional dependencies, set: IIB_SKIP_OPTIONAL_DEPS=1\n"
+            "Core image browsing features will still work without numpy in some cases."
+        ),
+    }
+    return hints.get(package_name, "")
 
 with open(req_file) as file:
     for package in file:
         try:
             package = package.strip()
+            if not package or package.startswith("#"):
+                continue
+            
             package_name = extract_package_name(package)
+            
+            # Skip optional packages if IIB_SKIP_OPTIONAL_DEPS is set
+            if SKIP_OPTIONAL and package_name in OPTIONAL_PACKAGES:
+                print(f"Skipping optional dependency: {package}")
+                continue
+            
             if not launch.is_installed(dist2package(package_name)):
                 launch.run_pip(f"install \"{package}\"", f"sd-webui-infinite-image-browsing requirement: {package}")
         except Exception as e:
             # Handle Unicode encoding errors on Windows
             try:
-                print(str(e))
+                error_msg = str(e)
             except UnicodeEncodeError:
-                print(repr(e))
+                error_msg = repr(e)
-            print(
+            
-                f"Warning: Failed to install {package}, some preprocessors may not work."
+            print(f"Error details: {error_msg}")
-            )
+            
+            # Provide helpful hints for optional packages
+            hint_msg = get_optional_package_hints(package_name)
+            if hint_msg:
+                print(hint_msg)
+            else:
+                print(f"Warning: Failed to install {package}, some features may not work.")
+            
+            print()