$ git clone -n https://src.fedoraproject.org/rpms/ffmpegthumbs.git /var/lib/mock/f40-build-1915210-25086/root/chroot_tmpdir/scmroot/ffmpegthumbs
Cloning into '/var/lib/mock/f40-build-1915210-25086/root/chroot_tmpdir/scmroot/ffmpegthumbs'...
$ git fetch origin 42dc7d24358419304c070b8f0124c880fdd8e2b6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ffmpegthumbs
 * [new ref]         42dc7d24358419304c070b8f0124c880fdd8e2b6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 42dc7d2 24.05.2