$ git clone -n https://src.fedoraproject.org/rpms/libmatroska.git /var/lib/mock/f40-build-2007791-45301/root/chroot_tmpdir/scmroot/libmatroska
Cloning into '/var/lib/mock/f40-build-2007791-45301/root/chroot_tmpdir/scmroot/libmatroska'...
$ git fetch origin f2a7f4845db5bb37cce8790c64e0301a773166b1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libmatroska
 * [new ref]         f2a7f4845db5bb37cce8790c64e0301a773166b1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f2a7f48 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild