$ git clone -n https://src.fedoraproject.org/rpms/fbb.git /var/lib/mock/f39-build-1532217-36222/root/chroot_tmpdir/scmroot/fbb
Cloning into '/var/lib/mock/f39-build-1532217-36222/root/chroot_tmpdir/scmroot/fbb'...
$ git fetch origin 912e2029f32eb089ebc01a3c0c82c901860183a1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fbb
 * [new ref]         912e2029f32eb089ebc01a3c0c82c901860183a1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 912e202 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild