$ git clone -n https://gitee.com/gcdota930915/grub2.git /var/lib/mock/dist-an23-build-548175-87757/root/chroot_tmpdir/scmroot/grub2
Cloning into '/var/lib/mock/dist-an23-build-548175-87757/root/chroot_tmpdir/scmroot/grub2'...
$ git fetch origin c8796490ed620b3accc7107b3146d9b435fa65bf:KOJI_FETCH_HEAD
From https://gitee.com/gcdota930915/grub2
 * [new ref]         c8796490ed620b3accc7107b3146d9b435fa65bf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c879649 Backport upstream 569214e2: fix GRUB ext2 driver misreading ext4 external extent tree (>4 extents)