Git, editors, package managers, local dev environments.
Most HTTP bugs can be pinned down with one tool you already have. This guide shows the curl options we use daily: verbose output, header-only requests, --resolve and --connect-to for testing servers before DNS changes, timing breakdowns, protocol versions and TLS checks.
A lockfile-only dependency bump passed CI and then broke production. Our cache key hashed package.json, not package-lock.json, so CI restored old node_modules and skipped npm ci. How we found it and rebuilt dependency caching we can trust.
A worker image built fine but every container exited at once with "no such file or directory" for a file that clearly existed. A Windows checkout had turned the shebang into /bin/bash with a carriage return. We fixed it with .gitattributes and a CI check.
Every engineer who downloaded our internal deploy helper got a "damaged" dialog. The app was fine; a CI step modified the bundle after signing and Gatekeeper checked the quarantined copy. We now sign, notarize and staple in the right order.
Our deploy ran composer update on a 2 GB server until the resolver ran out of memory. Raising the limit let the OOM killer take MySQL instead. Committing the lock file exposed a second bug: it had been resolved on PHP 8.4 for a PHP 8.2 server.
A developer committed a .env file with a live AWS access key, then deleted it in the next commit. The key stayed in history. We revoked it within 40 minutes, checked CloudTrail, rewrote history with git filter-repo and added scanning so it cannot happen again.
Bumping React to 19 made npm install fail with ERESOLVE. The quick --legacy-peer-deps workaround installed, then crashed tooltips in staging. We learned to read the conflict, upgrade the real offender and use overrides only as a short, tested bridge.
A new Android Studio with JDK 21 forced a Gradle upgrade, the Gradle upgrade pulled in AGP 8, and AGP 8 rejected two old Flutter plugins with Namespace not specified. How we untangled the Gradle, AGP, Kotlin and JDK chain.
A hotfix made on a checked-out tag vanished when the developer switched back to main, and a reset --hard later took a day of work with it. Nothing was really gone: the reflog still pointed at every commit. Here is how we got them back and what gc changes.