Solved errors

Direct solutions to common programming errors and system issues.

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golang go error import gopath
3 min readBeginner

Fix Go Error: "cannot find package" / "cannot find module providing package" (2026)

Fix Go's "cannot find package" and "cannot find module providing package" errors. Covers the GOPATH-era vs module-era message, import path typos, go get, replace directives, vendoring, and internal package rules.

golang go error panic slice
3 min readBeginner

Fix Go Panic: "index out of range" Runtime Error (2026)

Fix Go's "panic: runtime error: index out of range" crash. Learn how to read the panic message, the len vs cap distinction, and defensive patterns that keep slice and array access safe.

golang go error go.sum go.mod
4 min readBeginner

Fix Go Error: "missing go.sum entry for module providing package" (2026)

Fix Go's "missing go.sum entry for module providing package" error. Learn why go.mod and go.sum diverge, how go mod tidy fixes it, the GOFLAGS=-mod=mod caveat, and vendor mode gotchas.

golang
4 min readBeginner

SOLVED: function main is undeclared in the main package (Go)

Fix Go error "function main is undeclared in the main package". Causes: wrong package name, missing main(), running go run on wrong file, or build tags.

git gpg linux
4 min readBeginner

SOLVED: gpg signing failed: inappropriate ioctl for device

Fix "gpg signing failed: inappropriate ioctl for device" when doing git commit. Set GPG_TTY, restart gpg-agent, or use pinentry-mode loopback.

python postgresql pip
4 min readBeginner

SOLVED: error: pg_config executable not found (psycopg2 pip install)

Fix "error: pg_config executable not found" when pip install psycopg2 fails. Install postgresql-dev headers or use psycopg2-binary instead.

docker permission denied docker group rootless docker linux
6 min readBeginner

Fix Docker 'Permission Denied' Error (2026) — All Causes

Fix "Got permission denied while trying to connect to the Docker daemon socket" in 2026. All causes: docker group, socket permissions, rootless Docker, sudo workaround.

golang go type error type conversion
6 min readIntermediate

Fix 'cannot use X (type Y) as type Z' in Go — Type Mismatch Guide

Fix 'cannot use X (type Y) as type Z' in Go. Covers explicit conversions, interface satisfaction, pointer vs value receivers, and type assertions with the ok pattern.

golang go error compile variables
5 min readBeginner

Fix 'declared and not used' Error in Go (2026)

Fix Go's 'declared and not used' compile error. Learn why Go enforces this, how to use the blank identifier _, and common cases like loop variables and error returns.

golang go error compile main package
6 min readBeginner

Fix: "function main is undeclared in the main package" in Go

Fix the Go error "runtime.main_main·f: function main is undeclared in the main package". Covers all 5 causes with code examples and step-by-step solutions.