$ git clone -n https://src.fedoraproject.org/rpms/perl-Diff-LibXDiff.git /var/lib/mock/f45-build-23182-596/root/chroot_tmpdir/scmroot/perl-Diff-LibXDiff
Cloning into '/var/lib/mock/f45-build-23182-596/root/chroot_tmpdir/scmroot/perl-Diff-LibXDiff'...
$ git fetch origin c5b8be8e82ace07b9e1d6b16583692194a1f0672:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Diff-LibXDiff
 * [new ref]         c5b8be8e82ace07b9e1d6b16583692194a1f0672 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c5b8be8 Perl 5.44 rebuild