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

go 1.12

require example.com/retractdep v1.0.0
-- go.sum --
example.com/retractdep v1.0.0 h1:SOVn6jA2ygQY+v8/5aAwxVUJ9teuLrdH/UmbUtp2C44=
example.com/retractdep v1.0.0/go.mod h1:UjjWSH/ulfbAGgQQwm7pAZ988MFRngUSkJnzcuPsYDI=
-- a.go --
package a

import _ "example.com/retractdep"