$ git clone -n https://src.fedoraproject.org/rpms/rust-git2_0.16.git /var/lib/mock/f40-build-2656096-66913/root/chroot_tmpdir/scmroot/rust-git2_0.16
Cloning into '/var/lib/mock/f40-build-2656096-66913/root/chroot_tmpdir/scmroot/rust-git2_0.16'...
$ git fetch origin 191d6525e4e4d2d2ad6e05111d6943336ddc3bef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-git2_0.16
 * [new ref]         191d6525e4e4d2d2ad6e05111d6943336ddc3bef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 191d652 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild