Update yamale dependency to version > 6.0 for Python 3.14 compatibility #189
Description
Description
The current version of chart-testing-action includes yamale version 4.x, which is incompatible with Python 3.14 due to the removal of deprecated AST attributes (ast.Num, ast.Str, etc.). This causes chart linting to fail when running on systems with Python 3.14.
Current Behavior
Chart linting fails with the following error during YAML schema validation:
Validating /home/runner/work/manifests/manifests/helm/oauth2-proxy/Chart.yaml...
Traceback (most recent call last):
File "/opt/hostedtoolcache/ct/3.12.0/amd64/venv/bin/yamale", line 7, in <module>
sys.exit(main())
File "/opt/hostedtoolcache/ct/3.12.0/amd64/venv/lib/python3.14/site-packages/yamale/command_line.py", line 124, in main
_router(args.path, args.schema, args.cpu_num, args.parser, not args.no_strict)
...
File "/opt/hostedtoolcache/ct/3.12.0/amd64/venv/lib/python3.14/site-packages/yamale/syntax/parser.py", line 22, in _validate_expr
ast.Constant, ast.Num, ast.Str, ast.Bytes, ast.NameConstant]
^^^^^^^
AttributeError: module 'ast' has no attribute 'Num'
failed linting charts: failed processing charts
Error: Process completed with exit status 1.
Expected Behavior
Chart linting should complete successfully on Python 3.14.
Proposed Solution
Update the yamale dependency to version > 6.0, which includes Python 3.14 compatibility and replaces the deprecated AST attributes with ast.Constant.
Reference: yamale releases
Additional Context
- This issue is affecting our CI pipeline: chore(deps): update helm release redis-ha to v4.35.3 oauth2-proxy/manifests#371
- Python 3.14 removed
ast.Num,ast.Str,ast.Bytes, andast.NameConstant(deprecated since Python 3.8) - yamale 5.x addresses this compatibility issue
Workaround
Currently, users can work around this by explicitly pinning Python to version 3.12 or earlier in their workflows, but this is not a sustainable long-term solution.
Thank you for maintaining this valuable tool!