$ go build "$buildFlags"
flag provided but not defined: -tags 'ec2 systemd cpython process log'
usage: go build [-o output] [-i] [build flags] [packages]
Run 'go help build' for details.

$ go build $buildFlags
invalid value "'ec2" for flag -tags: unterminated ' string
usage: go build [-o output] [-i] [build flags] [packages]
Run 'go help build' for details.

$ echo $buildFlags
-tags 'ec2 systemd cpython process log'