$ git clone -n https://src.fedoraproject.org/rpms/ffmpegthumbnailer.git /var/lib/mock/f42-build-868874-176304/root/chroot_tmpdir/scmroot/ffmpegthumbnailer
Cloning into '/var/lib/mock/f42-build-868874-176304/root/chroot_tmpdir/scmroot/ffmpegthumbnailer'...
$ git fetch origin ca5eb9bf59aa4456dd37988c82b3aab73ad9effa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ffmpegthumbnailer
 * [new ref]         ca5eb9bf59aa4456dd37988c82b3aab73ad9effa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca5eb9b Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild