cfn-lint: Incompatible with Python 3.14 #255029
Description
brew config AND brew doctor output OR brew gist-logs <formula> link
brew config
HOMEBREW_VERSION: 5.0.2
ORIGIN: https://github.com/Homebrew/brew
HEAD: d6b691d839ee05869772f1a233bf8173ccaeea51
Last commit: 3 days ago
Branch: stable
Core tap JSON: 19 Nov 10:09 UTC
Core cask tap JSON: 19 Nov 10:09 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DOWNLOAD_CONCURRENCY: 32
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 16
Homebrew Ruby: 3.4.7 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.4.7/bin/ruby
CPU: 16-core 64-bit arm_brava
Clang: 17.0.0 build 1700
Git: 2.50.1 => /Applications/Xcode.app/Contents/Developer/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 26.1-arm64
CLT: 26.1.0.0.1.1761104275
Xcode: 26.1
Rosetta 2: false
brew doctor
Your system is ready to brew.Verification
- My
brew doctoroutput saysYour system is ready to brew.and am still able to reproduce my issue. - I ran
brew updateand am still able to reproduce my issue. - I have resolved all warnings from
brew doctorand that did not fix my problem. - I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates.
- My issue is not about a failure to build a formula from source.
What were you trying to do (and why)?
Tried to use cfn-lint to lint a CloudFormation template file. The contents of the template does not matter as long as it's valid.
brew install cfn-lint
cfn-lint budgets.yml
What happened (include all command output)?
Running cfn-lint always produces following warning:
/opt/homebrew/Cellar/cfn-lint/1.41.0/libexec/lib/python3.14/site-packages/samtranslator/compat.py:2: UserWarning: Core Pydantic V1 functionality isn't compatible with Python 3.14 or greater.
from pydantic import v1 as pydantic
What did you expect to happen?
cfn-lint should not produce any output when template is valid. Many tools that rely on cfn-lint output parsing such as VS Code Cloudformation linter extension parses this as an warning on any open CloudFormation template file.
Did started after #250169 but following issues and PRs are probably related:
Seems that cfn-lint does not support Python 3.14 officially yet: aws-cloudformation/cfn-lint#4266 which is related to this upstream dependency: aws/serverless-application-model#3831
Step-by-step reproduction instructions (by running brew commands)
brew install cfn-lint
cfn-lint budgets.yml