$ git clone -n https://src.fedoraproject.org/rpms/E.git /var/lib/mock/f40-build-2209218-52150/root/chroot_tmpdir/scmroot/E
Cloning into '/var/lib/mock/f40-build-2209218-52150/root/chroot_tmpdir/scmroot/E'...
$ git fetch origin 8978a9f531e1a0e38880a8c9e0a460ce2e7214d4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/E
 * [new ref]         8978a9f531e1a0e38880a8c9e0a460ce2e7214d4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8978a9f Version 3.0.03