Module example.com/ambiguous/a/b is a suffix of example.com/a.
This version contains no package.
-- .mod --
module example.com/ambiguous/a/b

go 1.16
-- .info --
{"Version":"v0.0.0-empty"}
-- go.mod --
module example.com/ambiguous/a/b

Module with a function that prints file name for the top stack frame.
Different versions of this module are identical, but they should return
different file names with -trimpath.
-- .mod --
module example.com/stack

go 1.14
-- .info --
{"Version":"v1.0.0"}
-- stack.go --
package stack

import "runtime"

func TopFile() string {
	_, file, _, _ := runtime.Caller(0)
	return file

Module with a function that prints file name for the top stack frame.
Different versions of this module are identical, but they should return
different file names with -trimpath.
-- .mod --
module example.com/stack

go 1.14
-- .info --
{"Version":"v1.0.1"}
-- stack.go --
package stack

import "runtime"

func TopFile() string {
	_, file, _, _ := runtime.Caller(0)
	return file

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

go 1.19

retract v1.0.0 // bad

-- .info --

A module which has no root package.

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

Written by hand.
Test case for package moved into a parent module.

-- .mod --
module example.com/join/subpkg
-- .info --
{"Version": "v1.0.0"}
-- x.go --

example.com/cmd contains main packages.

-- .info --
{"Version":"v1.0.0-newerself"}
-- .mod --
module example.com/cmd

go 1.16

require example.com/cmd v1.0.0
-- go.mod --
module example.com/cmd

go 1.16

require example.com/cmd v1.0.0
-- a/a.go --
package main

func main() {}
-- b/b.go --
package main

func main() {}
-- err/err.go --
package err

patch.example.com/direct v1.0.0
written by hand

-- .mod --
module patch.example.com/direct

require (
	patch.example.com/indirect v1.0.0
)
-- .info --
{"Version":"v1.0.0"}
-- go.mod --
module patch.example.com/direct

require (
	patch.example.com/indirect v1.0.0
)
-- direct.go --
package direct

patch.example.com/direct v1.0.1
written by hand

-- .mod --
module patch.example.com/direct

require (
	patch.example.com/indirect v1.0.0
	patch.example.com/depofdirectpatch v1.0.0
)
-- .info --
{"Version":"v1.0.1"}
-- go.mod --
module patch.example.com/direct

require (
	patch.example.com/indirect v1.0.0
	patch.example.com/depofdirectpatch v1.0.0
)
-- direct.go --
package direct

build-lifecycle-example.png...