vendor/github.com/moby/buildkit/frontend/dockerfile/instructions/commands_ssh.go - third_party/github.com/docker/docker - Git at Google

 // +build dfssh

 package instructions

 func isSSHMountsSupported() bool {
 	return true
 }
	// +build dfssh

	package instructions

	func isSSHMountsSupported() bool {
	return true
	}