$ git clone -n https://src.fedoraproject.org/rpms/libtommath.git /var/lib/mock/f40-build-784544-133440/root/chroot_tmpdir/scmroot/libtommath
Cloning into '/var/lib/mock/f40-build-784544-133440/root/chroot_tmpdir/scmroot/libtommath'...
$ git fetch origin eb77a6cd754eb9a59817bf2a285899235ceae770:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtommath
 * [new ref]         eb77a6cd754eb9a59817bf2a285899235ceae770 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at eb77a6c Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild