with the same version.

-- .mod --
module example.net/ambiguous

go 1.16
-- .info --
{"Version": "v0.1.0"}
-- go.mod --
module example.net/ambiguous

go 1.16
-- nested/pkg/pkg.go --
// Package pkg exists in both example.net/ambiguous v0.1.0
// and example.net/ambiguous/nested v0.1.0

Written by hand.
Test module with a root package added in v1.1.0
and a subpackage added in v1.2.0.

-- .mod --
module example.net/pkgadded

go 1.16
-- .info --
{"Version":"v1.0.0"}
-- go.mod --
module example.net/pkgadded

go 1.16
-- README.txt --
We will add the package example.net/pkgadded in v1.1.0,

example.com/downgrade v2.0.0
written by hand

-- .mod --
module example.com/downgrade

require rsc.io/quote v1.5.2
-- .info --

example.com/version v1.0.0
written by hand

-- .mod --
module example.com/version
-- .info --
{"Version":"v1.0.0"}
-- version.go --
package version

example.com/version v1.0.1
written by hand

-- .mod --
module example.com/version
-- .info --
{"Version":"v1.0.1"}
-- version.go --
package version

-- .mod --
module example.com/retract/ambiguous

go 1.16
-- .info --
{"Version":"v1.0.0"}
-- nested/nested.go --

example.com/printversion v0.1.0

-- .mod --
module example.com/printversion
-- .info --
{"Version":"v0.1.0"}
-- README.txt --
There is no go.mod file for this version of the module.
-- printversion.go --
package main

import (
	"fmt"
	"os"
	"runtime/debug"

	_ "example.com/version"
)

func main() {
	info, _ := debug.ReadBuildInfo()
	fmt.Fprintf(os.Stdout, "path is %s\n", info.Path)

Written by hand.
Test module with a root package added in v1.1.0
and a subpackage added in v1.2.0.

-- .mod --
module example.net/pkgadded

go 1.16
-- .info --
{"Version":"v1.1.0"}
-- go.mod --
module example.net/pkgadded

go 1.16
-- README.txt --
We will add the package example.net/pkgadded/subpkg in v1.2.0.
-- pkgadded.go --
// Package pkgadded was added in v1.1.0.

-- .info --
{"Version":"v1.0.0"}
-- .mod --
// Deprecated: in v1.0.0
module example.com/undeprecated

go 1.17
-- go.mod --
// Deprecated: in v1.0.0
module example.com/undeprecated

go 1.17
-- undeprecated.go --
package undeprecated

-- cmd/a/a.go --
package main

import "fmt"

example.com/generics v1.0.0
written by hand

-- .mod --
module example.com/generics

go 1.18
-- .info --
{"Version":"v1.0.0"}
-- go.mod --
module example.com/generics

go 1.18
-- generics.go --
package generics

type Int interface {
	~int
}