$ git clone -n https://src.fedoraproject.org/rpms/perl-JSON-Util.git /var/lib/mock/f45-build-24295-603/root/chroot_tmpdir/scmroot/perl-JSON-Util
Cloning into '/var/lib/mock/f45-build-24295-603/root/chroot_tmpdir/scmroot/perl-JSON-Util'...
$ git fetch origin 2947488cd0b4a0e307457b7225384eacda76a39e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-JSON-Util
 * [new ref]         2947488cd0b4a0e307457b7225384eacda76a39e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2947488 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild