$ git clone -n https://src.fedoraproject.org/rpms/perl-Ref-Util-XS.git /var/lib/mock/f45-build-26042-614/root/chroot_tmpdir/scmroot/perl-Ref-Util-XS
Cloning into '/var/lib/mock/f45-build-26042-614/root/chroot_tmpdir/scmroot/perl-Ref-Util-XS'...
$ git fetch origin 17cc3490b84cb238bc8ebe026c2408ef0ef3bff6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Ref-Util-XS
 * [new ref]         17cc3490b84cb238bc8ebe026c2408ef0ef3bff6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 17cc349 Perl 5.44 rebuild