I think the author is trying to do a no cgo build based on what the linked article is saying.
I remember somewhere that cgo/ndk is required for android (sometime after that article was posted) but I can't find anything to link to.
$ gcc --version
gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.