$ git clone -n https://src.fedoraproject.org/rpms/fex-emu-rootfs-fedora.git /var/lib/mock/f45-build-52008-905/root/chroot_tmpdir/scmroot/fex-emu-rootfs-fedora
Cloning into '/var/lib/mock/f45-build-52008-905/root/chroot_tmpdir/scmroot/fex-emu-rootfs-fedora'...
$ git fetch origin 863b45035f08871b3e8886319c599462c3b0d2f2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fex-emu-rootfs-fedora
 * [new ref]         863b45035f08871b3e8886319c599462c3b0d2f2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 863b450 fixup: Use .ero instead of .erofs