I downloaded the mender-artifact code with below command.
git clone https://github.com/mendersoftware/mender-artifact.git
after setting up env and go build got below error:
go build github.com/mendersoftware/mender-artifact: no non-test Go files in /src/github.com/mendersoftware/mender-artifact
make if you want to build mender-artifact. The same goes for the mender client.
Go build is not enough because we add additional steps to the build process.
Thank you @kacf. I had to install lzma which was missing and make build did build the binary.