$ git clone -n https://src.fedoraproject.org/rpms/perl-WWW-xkcd.git /var/lib/mock/f45-build-27408-624/root/chroot_tmpdir/scmroot/perl-WWW-xkcd
Cloning into '/var/lib/mock/f45-build-27408-624/root/chroot_tmpdir/scmroot/perl-WWW-xkcd'...
$ git fetch origin 1f96b52e4d3650a99a9fa1ec1b336ca266a5d12c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-WWW-xkcd
 * [new ref]         1f96b52e4d3650a99a9fa1ec1b336ca266a5d12c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1f96b52 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild