import a .gen package that is checked in, but doesn't require it in go.mod. go mod tidy fails with leading dot in path element
$ go mod tidy
go: finding github.com/xytan0056/depwithgen latest
github.com/xytan0056/gomodnorequire tested by
github.com/xytan0056/gomodnorequire.test imports
github.com/xytan0056/depwithgen/.gen/client: malformed module path "github.com/xytan0056/depwithgen/.gen/client": leading dot in path element