[hyporthogon]

Copypasta from other codebases happen to work better in non-production environments because the input space is smaller in virtually any non-prod runtime space than in prod.

This makes for a larger intersection of inputs to the copypasta that produce outputs that are expected by the blogpost/googling developer and inputs to the copypasta that produce outputs that are generated at non-prod runtime.

When you don't quickly see what's semantically wrong with the code (the problem mismatch) because you pasted it and it just worked (maybe with a few small tweaks), then you quickly forget about it and black-box the snippet in your head. Then, when input space gets real-world and things break, because the copypasta never had much cognitive gravity (because you didn't think much about it), it doesn't attract log dump elements in your log-scanning brain as much as stuff you had to think through yourself does.

I guess you could automate some static checks for this by some massive trawl of snippets from a few websites (at least popular SO posts in the same language?) and finding verbatim matches in your codebase. Sounds massively impractical to do this at scale though. Does anyone know tools that do this?