fix: resolve Gradio 502 startup error on WSL2 environments

[vijaykushwaha-03]

Hey! 👋

I ran into the issue described in #49 where the Gradio app crashes with a 502 error when running on WSL2. After some digging, I found the root cause and put together a fix.

What was happening

On WSL2, when you run python app.py, it fails with:

The problem is that WSL2 handles localhost networking differently than native Linux. Gradio tries to verify the server is running by pinging 127.0.0.1, but that doesn't work reliably in WSL2.

What I changed

• Added auto-detection for WSL2 environments (checks /proc/version and env variables)
• When WSL2 is detected, the app automatically binds to 0.0.0.0 instead of localhost
• Added some command-line flags (--server-name, --server-port, --share) so users can manually configure things if needed
• Applied the same fix to app_texturing.py for consistency

How to use it

For most people, it should just work now:

python app.py

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[Copilot]

Pull request overview

This PR addresses a Gradio 502 startup error that occurs when running the application on WSL2 environments by implementing WSL2 auto-detection and configurable server parameters.

Key Changes:

• Added WSL2 environment auto-detection that automatically binds to 0.0.0.0 for better compatibility
• Introduced command-line arguments (--server-name, --server-port, --share) for manual server configuration
• Applied the same fix consistently to both app.py and app_texturing.py

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
app.py	Added argparse for server configuration, WSL2 auto-detection logic, and updated demo.launch() to use configurable server parameters
app_texturing.py	Applied identical WSL2 detection and server configuration changes as app.py for consistency

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The file is being read twice in this line. The first f.read().lower() reads the entire file content, and then the second f.read().lower() is called on an empty file buffer since the file pointer is already at the end. This means the 'wsl' check will never match. Store the result of f.read().lower() in a variable first and then check both conditions against that variable.

Suggested change

	is_wsl = 'microsoft' in f.read().lower() or 'wsl' in f.read().lower()
	version_info = f.read().lower()
	is_wsl = 'microsoft' in version_info or 'wsl' in version_info

[Copilot]

Using a bare except clause without specifying an exception type is considered bad practice. It catches all exceptions including system-exiting exceptions like KeyboardInterrupt and SystemExit, which should typically not be caught. Specify the expected exception types (e.g., FileNotFoundError, IOError, OSError) to make the error handling more explicit and avoid masking unexpected errors.

Suggested change

	except:
	except OSError:
	# If /proc/version cannot be read, leave is_wsl as False and continue

[Copilot]

Using a bare except clause without specifying an exception type is considered bad practice. It catches all exceptions including system-exiting exceptions like KeyboardInterrupt and SystemExit, which should typically not be caught. Specify the expected exception types (e.g., FileNotFoundError, IOError, OSError) to make the error handling more explicit and avoid masking unexpected errors.

Suggested change

	except:
	except OSError:

[Copilot]

The WSL2 detection logic (lines 630-648) is duplicated between app.py and app_texturing.py. Consider extracting this into a shared utility function to improve maintainability and ensure consistency. This would make it easier to fix bugs (like the double file read issue) or add improvements in one place rather than maintaining the same code in multiple locations.

Suggested change

	# Auto-detect WSL2 environment and set appropriate server_name
	server_name = args.server_name
	if server_name is None:
	# Check if running in WSL2
	is_wsl = False
	try:
	with open('/proc/version', 'r') as f:
	is_wsl = 'microsoft' in f.read().lower() or 'wsl' in f.read().lower()
	except:
	pass
	# Also check WSL_DISTRO_NAME environment variable
	if os.environ.get('WSL_DISTRO_NAME') or os.environ.get('WSL_INTEROP'):
	is_wsl = True
	if is_wsl:
	server_name = "0.0.0.0"
	print("WSL2 environment detected. Using server_name='0.0.0.0' for better compatibility.")
	print("Access the app at http://localhost:{} from your Windows browser.".format(args.server_port))
	def _is_wsl2() -> bool:
	"""
	Detect whether the current environment is WSL2.
	Checks both /proc/version content and common WSL environment variables.
	"""
	# Check if running in WSL2 via /proc/version
	try:
	with open('/proc/version', 'r') as f:
	version_info = f.read().lower()
	if 'microsoft' in version_info or 'wsl' in version_info:
	return True
	except Exception:
	# If /proc/version cannot be read, fall back to environment variables
	pass
	# Also check WSL-related environment variables
	if os.environ.get('WSL_DISTRO_NAME') or os.environ.get('WSL_INTEROP'):
	return True
	return False
	# Auto-detect WSL2 environment and set appropriate server_name
	server_name = args.server_name
	if server_name is None and _is_wsl2():
	server_name = "0.0.0.0"
	print("WSL2 environment detected. Using server_name='0.0.0.0' for better compatibility.")
	print("Access the app at http://localhost:{} from your Windows browser.".format(args.server_port))

[Copilot]

The WSL2 detection logic (lines 157-175) is duplicated between app.py and app_texturing.py. Consider extracting this into a shared utility function to improve maintainability and ensure consistency. This would make it easier to fix bugs (like the double file read issue) or add improvements in one place rather than maintaining the same code in multiple locations.

[Copilot]

The file is being read twice in this line. The first f.read().lower() reads the entire file content, and then the second f.read().lower() is called on an empty file buffer since the file pointer is already at the end. This means the 'wsl' check will never match. Store the result of f.read().lower() in a variable first and then check both conditions against that variable.

Suggested change

	is_wsl = 'microsoft' in f.read().lower() or 'wsl' in f.read().lower()
	version_info = f.read().lower()
	is_wsl = 'microsoft' in version_info or 'wsl' in version_info