$ git clone -n https://src.fedoraproject.org/rpms/fftw2.git /var/lib/mock/f40-build-1996368-44008/root/chroot_tmpdir/scmroot/fftw2
Cloning into '/var/lib/mock/f40-build-1996368-44008/root/chroot_tmpdir/scmroot/fftw2'...
$ git fetch origin 5f301e3a5169b3d703c0af87c79bc812e56d830e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fftw2
 * [new ref]         5f301e3a5169b3d703c0af87c79bc812e56d830e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5f301e3 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild