error-reference.dev
One error. One page. One answer.
Developer error reference. Copy-paste fixes at the top, explanation below — no filler, no ads above the fold.
Categories
git — 33 pages
- git amend last commit message — rewrite without a new commit
- git bisect — find the commit that introduced a bug
- git cherry-pick — apply a commit from another branch
- git clone a specific branch
- git delete remote branch — push delete
- git detached HEAD — what it means and how to fix
- git diff between two branches
- git discard all unstaged changes
- git force pull / overwrite local changes
- git push rejected — file too large
- git line ending warning (CRLF / LF) — how to fix
- git merge conflict — how to resolve
- git permission denied (publickey) — how to fix
- git pull --rebase vs --merge — which to use
- git push rejected (non-fast-forward) — how to fix
- git rebase --abort — cancel a rebase in progress
- git recover deleted branch — using reflog
- git remote change URL — switch origin or add new remote
- git remove all untracked files and directories
- git rename a branch (local and remote)
- git reset --soft vs --mixed vs --hard — the difference
- git revert merge commit — how to undo a merge safely
- git convert shallow clone to full history
- git show a file at a specific commit
- git squash commits — combine commits before merging
- git SSL certificate problem — how to fix
- git stash drop — remove a specific stash
- git submodule update — initialize and update all submodules
- git tag a specific commit — create and push tags
- git undo last commit — keep or discard changes
- git stop tracking a file — remove from git without deleting
- git worktree — work on multiple branches simultaneously
docker — 21 pages
- docker build failed — no such file or directory
- docker cannot connect to daemon — is docker running?
- docker compose env — pass environment variables
- docker container exits immediately — how to debug
- docker container IP address — how to find
- docker container name already in use — how to fix
- docker copy files — between host and container
- docker env-file — load environment variables from .env
- docker exec — run command inside a running container
- docker health check — HEALTHCHECK instruction
- docker image not found — pull or build missing image
- docker multi-stage build — reduce image size
- docker network — connect containers
- docker no space left on device — clean up disk
- docker permission denied /var/run/docker.sock
- docker port already in use — address already in use
- docker prune images — remove unused images
- docker pull rate limit exceeded — how to fix
- docker remove all stopped containers
- docker logs — view and follow container output
- docker volume mount — persist data with -v and volumes
bash — 20 pages
- bash parse arguments with getopts and $@
- bash arrays — create, iterate, append, slice
- bash check exit code $?
- bash check if file or directory exists
- bash command not found — fix PATH and install
- bash cron job — schedule scripts with crontab
- bash date format — format dates with date command
- bash find files — find by name, type, and size
- bash for loop — iterate over files, arrays, ranges
- bash heredoc — multiline strings and stdin redirection
- bash kill process by port number
- bash no such file or directory — fix paths
- bash permission denied — chmod and file permissions
- bash pipe fail — pipefail and PIPESTATUS
- bash read file line by line
- bash redirect stderr — 2>&1 and separate streams
- bash set -e — exit script on error
- bash string comparison — test operators and [[ ]]
- bash syntax error near unexpected token
- bash xargs — build and execute commands from stdin
regex — 15 pages
- regex alternation — match one of multiple patterns
- regex anchors — ^ $ \b start, end, word boundary
- regex character classes — \d \w \s and ranges
- regex match date — YYYY-MM-DD and common formats
- regex match email address
- regex global replace — replace all matches
- regex match IP address — IPv4 validation
- regex lookahead and lookbehind — zero-width assertions
- regex multiline flag — ^ $ match line boundaries
- regex named capture groups — (?<name>...)
- regex non-greedy match — use *? and +? instead of * and +
- regex match phone number — international and US formats
- regex replace with capture group reference
- regex match URL — http, https, and optional path
- regex word boundary \b — match whole words only
npm — 16 pages
- npm audit fix — resolve security vulnerabilities
- npm engines field — require specific Node.js version
- npm ENOENT no such file or directory
- npm ERESOLVE unable to resolve dependency tree
- eslint version conflict with TypeScript — how to fix
- npm link — use a local package without publishing
- package-lock.json conflict — how to resolve
- npm ERR! missing script — how to fix
- npm peer dependency warning — how to handle
- npm Cannot find module — how to fix
- npm node-gyp build failed — how to fix
- npm cache clean and verify — fix corrupted installs
- npm outdated — check for package updates
- npm private registry — configure .npmrc
- npm scripts — define and run custom commands
- @scope/package-name — install and use scoped packages