$ 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'