$ whoami
root
$ git clone -n http://8.131.229.236/anolis-os/mesa-demos /var/lib/mock/dist-el8-build-6400-106/root/chroot_tmpdir/scmroot/mesa-demos
Cloning into '/var/lib/mock/dist-el8-build-6400-106/root/chroot_tmpdir/scmroot/mesa-demos'...
$ git reset --hard origin/a8
HEAD is now at 5f4b504 import mesa-demos-8.4.0-4.20181118git1830dcb.el8.src.rpm