“package XXX is not in GOROOT” when building a Go project

Question

In newer versions (post 1.13) of Go, you don’t need to set environment variables like GOPATH, GOBIN, etc.

You also need to have a go.mod file at the project root. This will make the directory a Go module. This is also where the .git/ is located. This means that only one go.mod is needed per repository. Inside the project root you could do a go mod init remote-repo.com/username/repository

I installed Go using Homebrew on macOS so GOROOT is /opt/homebrew/Cellar/go/1.17.5/libexec. This location contains the standard library and runtimes for Go.

test and run commands are run in the format go COMMAND package_path/xxx. Without specifying the package_path ./ and just running go COMMAND xxx, the compiler assumes that the module xxx is located in GOROOT, and throws error package xxx is not in GOROOT (path/to/GOROOT/src/xxx) because it doesn’t exist.

This behavior is expected because the package we are working with is not part of the Go SDK, i.e., not in GOROOT. The package we are working with will either end up in the go workspace or in the current working directory. Running go install compiles and puts an executable binary in $GOBIN (a.k.a $GOPATH/bin – here $GOPATH is the Go workspace). Running go build from inside a package compiles and puts an execuatble in that directory.

You haven’t listed the files inside the server/ package and which file has the main function, so I’ll emulate 3 workflows of a calculator each demonstrating more complexity. The last workflow is similar to your directory structure.

Directory Structure

Version 1:

Getting started with packages
Basic functionality

calculatorv1
├── go.mod                      <- go mod init github.com/yourname/calculatorv1
└── basic/
    ├── add.go
    ├── add_test.go
    ├── main.go
    ├── multiply.go
    └── multiply_test.go

Version 2:

More functionality
Multiple packages

calculatorv2
├── go.mod                      <- go mod init github.com/yourname/calculatorv2
├── main.go
└── basic/
│   ├── add.go
│   ├── add_test.go
│   ├── multiply.go
│   └── multiply_test.go
└─── advanced/
     ├── square.go
     └── square_test.go

Version 3:

Even more functionality
Nested packages

calculatorv3
├── go.mod                      <- go mod init github.com/yourname/calculatorv3
├── main.go
└── basic/
│   ├── add.go
│   ├── add_test.go
│   ├── multiply.go
│   └── multiply_test.go
└─── advanced/
     ├── square.go
     ├── square_test.go
     └── scientific/
         ├── declog.go
         └── declog_test.go

Workflow

Note: Substitute xxx with basic, advanced, or advanced/scientific depending on the version you’re working with.

Initialize Go module in the project directory (one of calculatorv1, calculatorv2, or calculatorv3) using go mod init
Run tests

go test -v ./... (from the project root, recursively execute all test suites)

OR

go test -v ./xxx (from the project root, run the test suite in package “xxx”)

OR
```
cd xxx/
go test -v            # (from inside the package)
```
Compile and execute package

go run ./... (from the project root, recursively run all .go files except tests)

OR

go run ./xxx (from the project root, run all .go files in “xxx” package except tests)

OR
```
cd xxx
go run .              # (from inside the package)
```
NOTE: Only files in the main package are executable, i.e., files having declaration package main. This means that go run ./xxx will only work with version1, and not versions 2 and 3. So instead for versions 2 and 3, run go run main.go

Code

Very easy to fill in incomplete bits

Version 1

add.go

package main

func addition(x int, y int) int {
    return x + y
}

add_test.go

package main

import "testing"

func TestAdd(t *testing.T) {

    t.Run("adding two positive numbers", func(t *testing.T) {
        sum := addition(2, 2)
        expected := 4
        
        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })
    
    t.Run("adding two negative numbers", func(t *testing.T) {
        sum := addition(-3, -4)
        expected := -7

        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })

    t.Run("adding one positive and one negative integer", func(t *testing.T) {
        sum := addition(1, -3)
        expected := -2

        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })
    
}

main.go

package main

import "fmt"

func main() {
    var num1 int = 1
    var num2 int = 2
    
    sum := addition(num1, num2)
    product := multiplication(num1, num2)

    fmt.Printf("The sum of %d and %d is %d\n", num1, num2, sum)
    fmt.Printf("The multiplication of %d and %d is %d\n", num1, num2, product)
}

Version 2

main.go

package main

import (
    "fmt"
    "github.com/yourname/calculatorv2/basic"
    "github.com/yourname/calculatorv2/advanced"
)

func main() {
    var num1 int = 1
    var num2 int = 2
    
    product := basic.Multiplication(num1, num2)
    square := advanced.Square(num2)

    fmt.Printf("The product of %d and %d is %d\n", num1, num2, product)
    fmt.Printf("The square of %d is %d\n", num2, square)
}

multiply.go

package basic

func Multiplication(x int, y int) int {
    return x * y
}

multiply_test.go

package basic

import "testing"

func TestMultiply(t *testing.T) {

    t.Run("multiplying two positive numbers", func(t *testing.T) {
        sum := Multiplication(2, 2)
        expected := 4
        
        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })
    
    t.Run("multiplying two negative numbers", func(t *testing.T) {
        sum := Multiplication(-3, -4)
        expected := 12

        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })

    t.Run("multiplying one positive and one negative integer", func(t *testing.T) {
        sum := Multiplication(1, -3)
        expected := -3

        if sum != expected {
            t.Errorf("Expected %d; but got %d", expected, sum)
        }
    })
    
}

square.go

package advanced

func Square(x int) int {
    return x * x
}

Version 3

main.go

package main

import (
    "fmt"
    "github.com/yourname/calculatorv3/basic"
    "github.com/yourname/calculatorv3/advanced"
    "github.com/yourname/calculatorv3/advanced/scientific"
)

func main() {
    var num1 int = 1
    var num2 int = 2
    var num3 float64 = 2
    
    product := basic.Multiplication(num1, num2)
    square := advanced.Square(num2)
    decimallog := scientific.DecimalLog(num3)

    fmt.Printf("The product of %d and %d is %d\n", num1, num2, product)
    fmt.Printf("The square of %d is %d\n", num2, square)
    fmt.Printf("The decimal log (base 10) of %f is %f\n", num3, decimallog)
}

square.go

package advanced

func Square(x int) int {
    return x * x
}

declog.go

package scientific

import "math"

func DecimalLog(x float64) float64 {
    return math.Log10(x)
}

declog_test.go

package scientific

import "testing"

func TestDecimalLog(t *testing.T) {

    t.Run("adding two positive numbers", func(t *testing.T) {
        sum := DecimalLog(100)
        expected := 2.0
        
        if sum != expected {
            t.Errorf("Expected %f; but got %f", expected, sum)
        }
    })
    
    t.Run("adding two negative numbers", func(t *testing.T) {
        sum := DecimalLog(10)
        expected := 1.0

        if sum != expected {
            t.Errorf("Expected %f; but got %f", expected, sum)
        }
    })
}

Directory Structure

Version 1:

Version 2:

Version 3:

Workflow

Code

Version 1

Version 2

Version 3

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