$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-BigInt-FastCalc.git /var/lib/mock/f40-build-779539-130368/root/chroot_tmpdir/scmroot/perl-Math-BigInt-FastCalc
Cloning into '/var/lib/mock/f40-build-779539-130368/root/chroot_tmpdir/scmroot/perl-Math-BigInt-FastCalc'...
$ git fetch origin b93619892cc32080cd95eeb2b7dc0331512f5740:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-BigInt-FastCalc
 * [new ref]         b93619892cc32080cd95eeb2b7dc0331512f5740 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b936198 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild