$ git clone -n https://src.fedoraproject.org/rpms/perl-rpm-build-perl.git /var/lib/mock/f45-build-27860-626/root/chroot_tmpdir/scmroot/perl-rpm-build-perl
Cloning into '/var/lib/mock/f45-build-27860-626/root/chroot_tmpdir/scmroot/perl-rpm-build-perl'...
$ git fetch origin fcf85aa89778217ef885f9ce8d0ed87559944bbe:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-rpm-build-perl
 * [new ref]         fcf85aa89778217ef885f9ce8d0ed87559944bbe -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fcf85aa Perl 5.44 rebuild