panic: sql: Register called twice for driver postgres

[jlpellicer]

I've seen this question asked before, but I could not find a solution.

My code before the migration works just fine (DB Ready to Rock), but when i add the migrate packages and code it doesn't.

The error:

panic: sql: Register called twice for driver postgres

goroutine 1 [running]:
database/sql.Register(0x1457227, 0x8, 0x163c460, 0x1698f30)
    /usr/local/go/src/database/sql/sql.go:50 +0x1ad
github.com/lib/pq.init.0()
    /Users/transistor/Documents/Go/src/github.com/lib/pq/conn.go:49 +0x5c
github.com/lib/pq.init()
    <autogenerated>:1 +0x782
github.com/mattes/migrate/database/postgres.init()
    <autogenerated>:1 +0x64
asc-api-go/db1.init()
    <autogenerated>:1 +0x5d
asc-api-go/controllers/roles.init()
    <autogenerated>:1 +0x50
asc-api-go/ascMiddleware.init()
    <autogenerated>:1 +0x5a
asc-api-go/server.init()
    <autogenerated>:1 +0x44
main.init()

This is my db file:

package db1

import (
    "database/sql"
    "log"
    "os"
    _ "github.com/lib/pq"
    "github.com/mattes/migrate"
    "github.com/mattes/migrate/database/postgres"
    _ "github.com/mattes/migrate/source/file"
)

var Db *sql.DB

func Connect() {
    var error error
    Db1ConnectString := os.Getenv("DB1_CONNECT_STRING")
    if Db1ConnectString == "" {
        log.Fatal("$DB1_CONNECT_STRING must be set")
    }

    Db, error = sql.Open("postgres", Db1ConnectString)
    if error != nil {
        log.Fatal(error)
    }

    error = Db.Ping()
    if error != nil {
        log.Fatal(error)
    }

    log.Println("DB1 Ready to Rock 🤘")

    driver, err := postgres.WithInstance(Db, &postgres.Config{})
    if err != nil {
        log.Fatal(error)
    }
    log.Print(driver)

    m, err := migrate.NewWithDatabaseInstance(
        "file:///Users/transistor/Documents/Go/src/asc-api-go/db1/migrations", 
        "myDB", 
        driver)
    if err != nil {
        log.Fatal(error)
    }

    err = m.Up()
    if err != nil {
        log.Fatal(err)
    }
}

I also read that there might be a "confilct" while using vendoring (I'm using Godep), and I do in fact have two pq libraries, but I don't know if this is a problem and therefore no idea how to solve it:

/Users/transistor/Documents/Go/src/asc-api-go/vendor/github.com/lib/pq

/Users/transistor/Documents/Go/src/github.com/lib/pq

Can you help? Thank you.

[eddieroger]

I was having this problem, and like other assorted comments mention, it has to do with loading lib/pg twice. The way I fixed it was moving the migrate in to my vendor directory and out of $GOPATH/src/github.com/.... It worked after that. The moral of that story is that if you use vendor, everything should be there, don't use it, but some packages get confused when loaded in both places.