Problem

Python 3.14 removed deprecated AST nodes (ast.Str, ast.Num, etc.) that were previously used by older versions of Werkzeug and Flask-BabelEx, causing installation failures:

AttributeError: module 'ast' has no attribute 'Str'

This prevented Lokole from installing on Ubuntu 26.04 (Python 3.14) and blocked IIAB Lokole role deployment.

Solution

Updated all dependencies to Python 3.14-compatible versions and migrated from deprecated packages:

Dependency Updates

• SQLAlchemy: 1.4.39 → 2.0.36 (Python 3.14 compatible)
• Celery: 5.2.7 → 5.4.0 (Python 3.14 compatible)
• Gunicorn: 20.1.0 → 23.0.0 (Python 3.14 compatible)
• Werkzeug: Already at 3.1.3 ✅
• Flask: Already at 3.1.3 ✅

Migration from flask_babelex to flask_babel

flask_babelex is deprecated and incompatible with Python 3.14. Migrated to flask_babel 4.0:

Changes:

• Replaced all from flask_babelex import ... with from flask_babel import ...
• Updated Babel locale selector API from decorator to parameter:

  # Old: @app.babel.localeselector
  # New: app.babel = Babel(app, locale_selector=get_locale)

Flask-Security-Too 5.8.0 Compatibility

Added required fields and updated configurations for Flask-Security-Too 4.0+ breaking changes:

• Added fs_uniquifier field to all User models (required in 4.0+)
• Updated SECURITY_USER_IDENTITY_ATTRIBUTES from string to dict format:

  # Old: SECURITY_USER_IDENTITY_ATTRIBUTES = 'email'
  # New: SECURITY_USER_IDENTITY_ATTRIBUTES = [{"email": {"mapper": lambda x: x}}]

• Replaced deprecated email_validator with valid_user_email in forms

Setup Configuration

• Added python_requires='>=3.12' to enforce minimum Python version
• Added Python 3.12/3.13/3.14 classifiers

IIAB Integration

• Added --upgrade flag to all pip install commands in IIAB Lokole role
• Added venv cleanup when lokole_commit or lokole_version is defined

Testing

✅ Tested on Python 3.12.12 - All imports successful, Flask CLI working
✅ Tested on Python 3.13.3 - All imports successful, Flask CLI working
✅ Tested on Python 3.14.3 - All imports successful, Flask CLI working
✅ IIAB Integration Tests - Full installation on Ubuntu 24.04/25.04/25.10/26.04 (pending)

Test Commands

# Python 3.14 verification
pyenv local 3.14.3
python -m pip install -e .
python -c "from opwen_email_client.webapp import create_app; print('✅ Flask app imports successfully')"
flask --app opwen_email_client.webapp manage --help

Ubuntu Compatibility Matrix

Breaking Changes

⚠️ Minimum Python version raised from 3.6+ to 3.12+

This is necessary because:

• Python 3.14 removed deprecated AST nodes
• Modern dependency versions require Python 3.12+
• Ubuntu 24.04 LTS (latest LTS) ships with Python 3.12

Related Issues

• Fixes Flask admin user creation on Python 3.14
• Resolves IIAB Lokole role installation on Ubuntu 26.04
• Addresses deprecated package warnings (flask_babelex)

Files Changed

• requirements-webapp.txt - Updated dependency versions
• setup.py - Added Python version constraints
• opwen_email_client/webapp/__init__.py - Migrated Babel API
• opwen_email_client/webapp/config.py - Updated imports and SECURITY config
• opwen_email_client/webapp/forms/login.py - Updated validators
• opwen_email_client/webapp/login.py - Added fs_uniquifier field
• opwen_email_client/domain/email/user_store.py - Added fs_uniquifier to interface
• opwen_email_server/integration/webapp.py - Implemented fs_uniquifier