$ git clone -n https://src.fedoraproject.org/rpms/rust-once_cell.git /var/lib/mock/f39-build-1462560-33345/root/chroot_tmpdir/scmroot/rust-once_cell
Cloning into '/var/lib/mock/f39-build-1462560-33345/root/chroot_tmpdir/scmroot/rust-once_cell'...
$ git fetch origin 2a4e96a44e7c29d4e3940d788777bf9bd8d2a34f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-once_cell
 * [new ref]         2a4e96a44e7c29d4e3940d788777bf9bd8d2a34f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2a4e96a Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild