How can I import a workspace as a dependency in another go repository?

I have a go multiple workspace project whose structure is:

apps/go.mod
go.work

The project includes a submodule apps and its go.work file has:

go 1.180
use (
./apps
)

I have another go project (separate repository) wants to import this app submodule as a library, below is go.mod:

module xxxx

go 1.18

require (
	github.com/zhaoyi0113/test-go-module v0.0.3 // indirect
)

then I have below code:

package main

import (
	"github.com/zhaoyi0113/test-go-module/apps/logger"
)

func main() {
	logger.Test()
}

It fails to compile with the error:

main.go:7:2: no required module provides package github.com/zhaoyi0113/test-go-module/apps/logger; to add it:
        go get github.com/zhaoyi0113/test-go-module/apps/logger

How can I import the submodule from the multiple workspaces project?

You cannot import a workspace.

Here's the current situation:

There is a module at github.com/zhaoyi0113/test-go-module/apps which declares its module path as github.com/zhaoyi0113/test-go-module. This module is not useable because the actual path to the module and the declared path do not match (notice that /apps is missing in one of the paths).

The xxxx module requires github.com/zhaoyi0113/test-go-module, but there there is no module found at the path. It's in the apps subdirectory as noted in the previous paragraph.

There are two possible fixes depending on where you want to place the module.

If you want to keep imported go.mod in it's current directory then update the module paths to include apps:

go.mod for imported module:

module github.com/zhaoyi0113/test-go-module/apps
go 1.19

go.mod for importing module:

module xxxx
go 1.18
require (
    github.com/zhaoyi0113/test-go-module/apps v0.0.3 // indirect
)

The second and conventional option
is to place the go.mod at the root of the project and put the go.work file outside of the project. To make this work, move go.mod to the root of the project (as it was in the initial commit) and move go.work somewhere else. No changes are required to the importing module.