feat: improve build backend and fix documentation

[turkalpmd]

Build System Improvements and Documentation Fixes

Summary

This pull request enhances the build system reliability, improves code quality, and fixes documentation issues in the gpt-oss project. And of course, I used GPT-o4 mini in many places.

Changes Made

Build Backend Enhancements (_build/gpt_oss_build_backend/backend.py)

Type Safety and Compatibility

• Added BuildBackendProtocol interface for type safety
• Replaced Union[X, None] with Optional[X] for Python <3.10 compatibility
• Added comprehensive type annotations throughout

Error Handling and Validation

• Implemented custom exceptions: BuildError and ConfigurationError
• Added directory validation with automatic creation
• Comprehensive try-catch blocks with proper error chaining
• Enhanced error messages with actionable guidance

Logging and Debugging

• Added structured logging functions (_log_info, _log_error)
• Detailed logging throughout build process
• Environment variable parsing with feedback
• Clear dependency requirement reporting

Configuration Management

• Improved GPTOSS_BUILD_METAL parsing (case-insensitive, whitespace-tolerant)
• Added configuration constants for maintainability
• Enhanced backend selection logic with validation

Architecture Improvements

• Added optional hooks for future PEP extensions
• Improved code organization and separation of concerns
• Added _safe_getattr utility for safer attribute access

Documentation Improvements (README.md)

Grammar and Typography Fixes

• Fixed punctuation: "memory.." → "memory."
• Corrected possessive: "Transformers's" → "Transformers'"
• Standardized compound words: "webserver" → "web server"
• Capitalized proper nouns: "python 3.12" → "Python 3.12"
• Improved sentence structure and flow
• Fixed prepositions: "on how to use" → "of how to use"
• Corrected articles: "a inference" → "an inference"
• Fixed verb forms: "recommend use" → "recommend using"
• Corrected plurals: "every two value" → "every two values"

Code Quality Fixes

Linting Error Resolution

• Added missing import structlog in chat_completions_sampler.py
• Removed unused nonlocal declarations in ollama.py
• Improved import organization

Benefits

For Developers

• Better debugging through comprehensive logging
• Improved type safety with Protocol interfaces
• Clear error messages with installation guidance
• Automatic directory creation prevents build failures

For Production

• Enhanced Python version compatibility
• Robust error handling reduces failures
• Structured logging enables better monitoring
• Maintainable, well-documented code

Testing

Code Quality

• All flake8 linting errors resolved
• Type hints compatible with mypy
• Import structure follows isort standards
• Ready for black code formatting

Build System

• Local testing of build backend improvements
• Error handling validation with various scenarios
• Environment variable parsing tested

Documentation

• Grammar and typography errors corrected
• Technical accuracy verified
• Readability and flow improved

Files Changed (except black/isort)

• README.md - Grammar fixes and typography improvements
• _build/gpt_oss_build_backend/backend.py - Complete build system enhancement
• gpt_oss/evals/chat_completions_sampler.py - Added missing import
• gpt_oss/responses_api/inference/ollama.py - Removed unused nonlocal

Backward Compatibility

All changes maintain existing API compatibility. No breaking changes introduced. Existing build processes continue to work with enhanced reliability and better error reporting.

Notes

These improvements provide a foundation for future enhancements while maintaining full backward compatibility. The build system is now more robust, the documentation is more professional, and the codebase follows modern Python practices.