$ git clone -n https://src.fedoraproject.org/rpms/perl-Exception-Class.git /var/lib/mock/f45-build-23416-597/root/chroot_tmpdir/scmroot/perl-Exception-Class
Cloning into '/var/lib/mock/f45-build-23416-597/root/chroot_tmpdir/scmroot/perl-Exception-Class'...
$ git fetch origin 2e9e19e149c91475b015f0a61928a1cce9c06a52:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Exception-Class
 * [new ref]         2e9e19e149c91475b015f0a61928a1cce9c06a52 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e9e19e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild