$ git clone -n https://src.fedoraproject.org/rpms/gnome-builder.git /var/lib/mock/f42-build-60978988-6587187/root/chroot_tmpdir/scmroot/gnome-builder
Cloning into '/var/lib/mock/f42-build-60978988-6587187/root/chroot_tmpdir/scmroot/gnome-builder'...
$ git fetch origin 69d307457f06b96a82478aa54b91312f3cbc5372:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-builder
 * [new ref]         69d307457f06b96a82478aa54b91312f3cbc5372 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 69d3074 Update to 48.2