从包的供应商处导入

Question

如何指定从供应商导入/使用软件包，而不是从GOPATH/GOROOT导入/使用软件包？

$GOPATH/src/
$GOPATH/src/github.com/
$GOPATH/src/github.com/myproject/mypkg
$GOPATH/src/github.com/myproject/mypkg/mypkgfile1.go

package mypkg
import "github.com/someproject/somepkg" // importing from vendor
type MyStruct struct {
Config somepkg.SomeStruct1
}
func New(config somepkg.SomeStruct1) MyStruct {...} 
func (m *MyStruct) DoSomething() {
a := somepkg.SomeStruct1{}
b := somepkg.SomeStruct2{}
// do something with 'a' and 'b'
out := somepkg.SomeFunc(a) 
}
func (m *MyStruct) MyFunc(input SomeStruct1) (output SomeStruct2, err error) {...}

$GOPATH/src/github.com/myproject/mypkg/mypkgfile2.go
$GOPATH/src/github.com/myproject/mypkg/vendor/github.com/someproject/somepkg/
$GOPATH/src/github.com/myproject/mypkg/vendor/github.com/someproject/somepkg/somepkgfile1.go

package somepkg
type SomeStruct1 struct {...}
type SomeStruct2 struct {...}
func SomeFunc(input SomeStruct1) (output SomeStruct2) {...}

$GOPATH/src/github.com/myproject/mypkg/go.mod

module gitHub.com/myproject/mypkg
go 1.1.4
require github.com/someproject/somepkg v1.0.0

$GOPATH/src/github.com/someproject/somepkg/somepkgfile1.go

package somepkg
type SomeStruct1 struct {...}
type SomeStruct2 struct {...}
func SomeFunc() {...}

$GOPATH/src/github.com/someproject/somepkg/go.mod

module gitHub.com/someproject/somepkg
go 1.1.4
require github.com/someproject/somepkg v1.0.0

$GOPATH/src/github.com/anotherproject/anotherpkpg/somepkgfile1.go

package main
import (
"github.com/someproject/somepkg"
"github.com/myproject/mypkg"
)
func main() {
// do something with somepkg
somepkg.SomeFunc()
s := somepkg.SomeStruct1{...} 
myData := mypkg.New(s) 
m := mypkg.MyFunc()
x := somepkg.SomeStruct1{...}
y := mypkg.MyFunc(x)
}

$GOPATH/src/github.com/someproject/somepkg/go.mod

module gitHub.com/someproject/somepkg
go 1.1.4
require (
github.com/myproject/mypkg v1.0.0
github.com/someproject/somepkg v1.0.0
)

当我构建/运行另一个pkpg/main.go时，我不断收到类型不匹配错误，例如：

cannot use &s (type *"someproject/somepkg".SomeStruct1) as type *"myproject/mypkg/vendor/github.com/someproject/somepkg".SomeStruct1 in argument to mypkg.New

根本不可能做到这一点？ 我知道如果 somepkg 的版本/版本不同，则可能会发生类型不匹配。 但是没有办法引用出售的某个 somepkg？ 我会认为当我

Answer 1

vendor

目录在GOPATH 模式下的工作方式与在模块模式下的工作方式不同。

由于github.com/myproject/mypkg/go.mod存在，您可能是在模块模式下构建github.com/myproject/mypkg及其依赖项。在模块模式下，仅使用主模块的vendor内容，并且始终忽略其他包的vendor目录，因此每个包只有一个位置和一个定义。(使用-mod=vendor时，每个包都是从vendor目录加载的;使用-mod=readonly或-mod=mod，每个包都是从模块缓存加载的。

由于github.com/anotherproject/anotherpkg/go.mod不存在，Go 1.15 及更早版本默认在 GOPATH 模式下构建它。在GOPATH模式下，每个目录中的import语句引用所有父目录的vendor子树中的包，并且即使供应商包共享相同的导入路径，它们也会被视为不同的包。

适合您的情况的正确长期解决方案可能是开始在模块模式下构建github.com/anotherproject/anotherpkg，并在需要时使用replace指令将其指向您的github.com/myproject/mypkg工作副本。

您可以使用一系列命令进行设置，例如：

# Enable module mode for anotherpkg.
cd $GOPATH/src/github.com/anotherproject/anotherpkg
go mod init github.com/anotherproject/anotherpkg
# Use the local copy of github.com/myproject/mypkg instead of the latest GitHub snapshot.
go mod edit -replace github.com/myproject/mypkg=$GOPATH/src/github.com/myproject/mypkg
go get -d github.com/myproject/mypkg
# Resolve any additional missing dependencies to their latest versions.
go mod tidy