$ git clone -n https://src.fedoraproject.org/rpms/gnome-calendar.git /var/lib/mock/f42-build-3305319-41426/root/chroot_tmpdir/scmroot/gnome-calendar
Cloning into '/var/lib/mock/f42-build-3305319-41426/root/chroot_tmpdir/scmroot/gnome-calendar'...
$ git fetch origin a3d03cb719acf95dafcebeb95c46ed55b9a12f1b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-calendar
 * [new ref]         a3d03cb719acf95dafcebeb95c46ed55b9a12f1b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a3d03cb Update to 48.rc