no required module provides package — how to fix

main.go:6:2: no required module provides package github.com/gorilla/mux; to add it:
	go get github.com/gorilla/mux
package example.com/app/internal/db is not in std (/usr/local/go/src/example.com/app/internal/db)

Quick fix: Add the dependency: go get github.com/gorilla/mux (or run go mod tidy to add all missing imports). For your own packages, the import must start with the module path from go.mod (e.g. example.com/app/internal/db). Make sure you run commands inside the module directory, and with GO111MODULE not set to off.

What it means

In module mode, every import must come from the standard library, your own module, or a module listed in go.mod (require). If no listed module contains the package, the go command stops with this error and helpfully suggests go get.

Show the module you are in:

go env GOMOD          # path to go.mod, or /dev/null if not in a module
head -3 go.mod        # module example.com/app

Cause 1: third-party dependency not added yet

go get github.com/gorilla/mux@latest
# or add every missing import at once:
go mod tidy

Commit both go.mod and go.sum. If you get missing go.sum entry afterwards, see missing go.sum entry.

Cause 2: the module path vs the package path

go get must find a module that contains the package. For major versions 2+, the import path includes the version suffix:

import "github.com/redis/go-redis/v9"      // correct for v9
import "github.com/jackc/pgx/v5/pgxpool"

Importing github.com/jackc/pgx/pgxpool (no /v5) looks for a package that only exists in v1-v4. Check the module's go.mod on pkg.go.dev for the exact path. Moved/renamed repos (e.g. github.com/go-redis/redis → github.com/redis/go-redis/v9) also cause this.

Cause 3: your own package with the wrong import path

Imports of local packages are relative to the module line, not the filesystem or GOPATH:

go.mod             -> module example.com/app
internal/db/db.go  -> package db
main.go            -> import "example.com/app/internal/db"

import "app/internal/db" or import "./internal/db" fails. If the error says package app/internal/db is not in std, the first path element doesn't match your module name. Fix the import, or change the module line (and all imports) consistently.

Cause 4: not inside the module

Running go run / go build from a parent directory, or on a single file outside the module, gives this error for every dependency. cd into the folder with go.mod. For several modules in one repo, use a workspace:

go work init ./api ./shared

Then imports of example.com/shared from api resolve locally. To use a local copy of a dependency without a workspace:

go mod edit -replace example.com/shared=../shared
go mod tidy

Cause 5: build tags, vendoring, GOFLAGS

• With a vendor/ directory, Go uses -mod=vendor by default. After adding a dependency, run go mod vendor.
• GOFLAGS=-mod=mod or -mod=readonly in CI changes whether go.mod can be updated; in readonly mode you must commit the updated go.mod.
• GO111MODULE=off forces the old GOPATH mode: go env -u GO111MODULE.

Cause 6: private modules

For private repositories go get fails to download, then reports the package as missing. Tell Go to skip the public proxy and checksum DB:

go env -w GOPRIVATE=github.com/myorg/*
git config --global url."git@github.com:".insteadOf "https://github.com/"
go get github.com/myorg/lib

Last updated 2026-11-07.