Checklists for software errors, setup, and tool workflows.

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Latest checklists

When your Python project uses multiple requirements files—for example, requirements/base.tx...

Fix Git 'index.lock file exists' Error
When you see the error fatal: Unable to create 'path/.git/index.lock': File exists....

Fix npm run build failing due to ESLint errors
You run npm run build and it fails with a wall of ESLint errors. This is common when...

Fix Git Push Rejected Non Fast Forward Error
You try to push your local commits to a remote repository and get: ! [rejected] —

Fix Cloudflare Wildcard Subdomain DNS Propagation Delay
You set up a wildcard DNS record (e.g., *.example.com) in Cloudflare, but new subdom...

Git index.lock File Exists: Quick Fix Checklist
You try to run a Git command and see fatal: Unable to create 'path/.git/index.lock'...