Go get all dependencies returns unrecognized import path for Terratest

Question

Configuration

• go1.15.2 darwin/amd64
• macOS Catalina v10.15.7

.zshrc file

export GOPATH=$HOME/go
export GOROOT=/usr/local/opt/go/libexec
export PATH=$PATH:$GOPATH/bin
export PATH=$PATH:$GOROOT/bin

What I'm trying to do

I'm new to Go, and trying to use Terratest to write a test for a Packer build.

When trying to run go test my_test.go I keep getting errors saying I need to install missing packages.

../../../../../go/src/github.com/gruntwork-io/terratest/modules/aws/sqs.go:10:2: cannot find package "github.com/google/uuid" in any of:
/usr/local/opt/go/libexec/src/github.com/google/uuid (from $GOROOT) /Users/username/go/src/github.com/google/uuid (from $GOPATH).
FAIL command-line-arguments [setup failed]
FAIL

Googling around I found that running go get -u ./... from the directory where my test file is should install these packages

Problem

When I run go get -u ./... I get the following error:

package _/Users/username/github.com/my-org/my-repo/packer/tests: unrecognized import path "_/Users/username/github.com/my-org/my-repo/packer/tests": import path does not begin with hostname

For additional context, this is the directory structure I'm using:

~ 
    github.com/my-org/my-repo/
        packer/
            tests/
                my_test.go

And here is the test file, which I've created using this terratest example as a reference:

package test

import (
    "testing"

    "github.com/gruntwork-io/terratest/modules/packer"
    "github.com/stretchr/testify/assert"
    terratest_aws "github.com/gruntwork-io/terratest/modules/aws"
)

func TestMyAmiBuild( t *testing.T) {

    awsRegion := "us-east-1"

    packerOptions := &packer.Options{
        // Path to the Packer template under test
        Template: "../template/template.json",

        // Variables to pass to Packer build
        Vars: map[string]string{
            "ami_name": "my-ami"
        },

        // Only build the AWS AMI
        Only: "amazon-ebs",
    }

    // Build the Packer template
    amiID := packer.BuildArtifact(t, packerOptions)

    // Clean up the AMI after we're done
    defer terratest_aws.DeleteAmiAndAllSnapshots(t, awsRegion, amiID)

    // Check if AMI is private
    amiIsPublic := terratest_aws.GetAmiPubliclyAccessible(t, awsRegion, amiID)
    assert.False(t, amiIsPublic)
}