cp go.mod go.mod.orig
go mod tidy
cmp go.mod go.mod.orig

-- go.mod --
module example.com/tidy

go 1.16

require (
	example.net/incomplete v0.1.0
	example.net/indirect v0.2.0 // indirect
	example.net/toolow v0.1.0
)

replace (
	example.net/incomplete v0.1.0 => ./incomplete
	example.net/indirect v0.1.0 => ./indirect.1
	example.net/indirect v0.2.0 => ./indirect.2
	example.net/toolow v0.1.0 => ./toolow
)
-- tidy.go --
package tidy

import (
	_ "example.net/incomplete"
	_ "example.net/toolow"
)

-- incomplete/go.mod --
module example.net/incomplete

go 1.16

// This module omits a needed requirement on example.net/indirect.
-- incomplete/incomplete.go --
package incomplete

import _ "example.net/indirect/newpkg"

-- toolow/go.mod --
module example.net/toolow

go 1.16

require example.net/indirect v0.1.0
-- toolow/toolow.go --
package toolow

import _ "example.net/indirect/oldpkg"

-- indirect.1/go.mod --
module example.net/indirect

go 1.16
-- indirect.1/oldpkg/oldpkg.go --
package oldpkg


-- indirect.2/go.mod --
module example.net/indirect

go 1.16
-- indirect.2/oldpkg/oldpkg.go --
package oldpkg
-- indirect.2/newpkg/newpkg.go --
package newpkg