$ git clone -n https://src.fedoraproject.org/rpms/golang-github-eclipse-paho-mqtt.git /var/lib/mock/f42-build-866345-173896/root/chroot_tmpdir/scmroot/golang-github-eclipse-paho-mqtt
Cloning into '/var/lib/mock/f42-build-866345-173896/root/chroot_tmpdir/scmroot/golang-github-eclipse-paho-mqtt'...
$ git fetch origin e2e8317d5fcddcf6c1f1680eaf223dbbc3299846:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-eclipse-paho-mqtt
 * [new ref]         e2e8317d5fcddcf6c1f1680eaf223dbbc3299846 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e2e8317 Update to 1.5.0 (RHBZ#2302130)