cmd/go: go build gets "cannot load http: cannot find module providing package http"

[AaronJan]

What version of Go are you using (go version)?

$ go version
go version go1.12.5 windows/amd64

Does this issue reproduce with the latest release?

Yes, I am using the latest version.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\Aaron\AppData\Local\go-build
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=C:\Users\Aaron\code\go-projects-win;C:\Go;
set GOPROXY=
set GORACE=
set GOROOT=C:\Go
set GOTMPDIR=
set GOTOOLDIR=C:\Go\pkg\tool\windows_amd64
set GCCGO=gccgo
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\Users\Aaron\code\my-blog\go.mod
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\Aaron\AppData\Local\Temp\go-build355843062=/tmp/go-build -gno-record-gcc-switches

What did you do?

I am using Windows and PowerShell.

I created a project at C:\Users\Aaron\code\my-blog\, then:

go mod init my-git-server/golang/my-blog

Here are my files:

main.go (Copied from gin):

package main

import (
    "http"

    "github.com/gin-gonic/gin"
)

var db = make(map[string]string)

func setupRouter() *gin.Engine {
    // Disable Console Color
    // gin.DisableConsoleColor()
    r := gin.Default()

    // Ping test
    r.GET("/ping", func(c *gin.Context) {
        c.String(http.StatusOK, "pong")
    })

    // Get user value
    r.GET("/user/:name", func(c *gin.Context) {
        user := c.Params.ByName("name")
        value, ok := db[user]

        if ok {
            c.JSON(http.StatusOK, gin.H{"user": user, "value": value})
        } else {
            c.JSON(http.StatusOK, gin.H{"user": user, "status": "no value"})
        }
    })

    // Authorized group (uses gin.BasicAuth() middleware)
    // Same than:
    // authorized := r.Group("/")
    // authorized.Use(gin.BasicAuth(gin.Credentials{
    //   "foo": "bar",
    //   "manu": "123",
    //}))
    authorized := r.Group("/", gin.BasicAuth(gin.Accounts{
        "foo": "bar", // user:foo password:bar
        "manu": "123", // user:manu password:123
    }))

    authorized.POST("admin", func(c *gin.Context) {
        user := c.MustGet(gin.AuthUserKey).(string)

        // Parse JSON
        var json struct {
            Value string `json:"value" binding:"required"`
        }

        if c.Bind(&json) == nil {
            db[user] = json.Value
            c.JSON(http.StatusOK, gin.H{"status": "ok"})
        }
    })

    return r
}

func main() {
    r := setupRouter()

    r.Run(":8080")
}

go.mod:

module my-git-server/golang/my-blog

go 1.12

require github.com/gin-gonic/gin v1.4.0

go.sum:

github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/gin-contrib/sse v0.0.0-20190301062529-5545eab6dad3 h1:t8FVkw33L+wilf2QiWkw0UV77qRpcH/JHPKGpKa2E8g=
github.com/gin-contrib/sse v0.0.0-20190301062529-5545eab6dad3/go.mod h1:VJ0WA2NBN22VlZ2dKZQPAPnyWw5XTlK1KymzLKsr59s=
github.com/gin-gonic/gin v1.4.0 h1:3tMoCCfM7ppqsR0ptz/wi1impNpT7/9wQtMZ8lr1mCQ=
github.com/gin-gonic/gin v1.4.0/go.mod h1:OW2EZn3DO8Ln9oIKOvM++LBO+5UPHJJDH72/q/3rZdM=
github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
github.com/json-iterator/go v1.1.6 h1:MrUvLMLTMxbqFJ9kzlvat/rYZqZnW3u4wkLzWTaFwKs=
github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=
github.com/mattn/go-isatty v0.0.7 h1:UvyT9uN+3r7yLEYSlJsbQGdsaB/a0DlgWP3pql6iwOc=
github.com/mattn/go-isatty v0.0.7/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
github.com/modern-go/reflect2 v1.0.1 h1:9f412s+6RmYXLWZSEzVVgPGK7C2PphHj5RJrvfx9AWI=
github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/ugorji/go v1.1.4 h1:j4s+tAvLfL3bZyefP2SEWmhBzmuIlH/eqNuPdFPgngw=
github.com/ugorji/go v1.1.4/go.mod h1:uQM

Then when I execute this command in my project folder (Actually this is from VSCode' s Go extension):

> C:\Go\bin\go.exe build -o C:\Users\Aaron\AppData\Local\Temp\vscode-goefkeiw\go-code-check .

But simple go build . gets the same output.

What did you expect to see?

It shouldn't emit any error message (I think).

I searched the internet, GitHub, and read this article, but I still can't find answer for my situation (maybe it's a silly mistake made by myself).

At first, I get this error on Windows WSL, so I reinstall Golang on Windows, but still can't get it working. Am I using this wrong?

What did you see instead?

I get this:

build my-git-server/golang/my-blog: cannot load http: cannot find module providing package http

But when I remove the github.com/gin-gonic/gin import statement (and code), only keep built-in packages, it works fine.

[AaronJan]

OMG...

Turns out it is my problem, http should be net/http.. I shouldn't overthinking about this.

I'm speechless..

Thanks.