//	GO_EXTLINK_ENABLED
//		Whether the linker should use external linking mode
//		when using -linkmode=auto with code that uses cgo.
//		Set to 0 to disable external linking mode, 1 to enable it.
//	GIT_ALLOW_PROTOCOL
//		Defined by Git. A colon-separated list of schemes that are allowed
//		to be used with git fetch/clone. If set, any scheme not explicitly
//		mentioned will be considered insecure by 'go get'.