$ git clone -n https://src.fedoraproject.org/rpms/perl-XML-Writer-String.git /var/lib/mock/f45-build-27664-625/root/chroot_tmpdir/scmroot/perl-XML-Writer-String
Cloning into '/var/lib/mock/f45-build-27664-625/root/chroot_tmpdir/scmroot/perl-XML-Writer-String'...
$ git fetch origin 2812e9519a95485b7fdc69f88c3899a7ec51f220:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-XML-Writer-String
 * [new ref]         2812e9519a95485b7fdc69f88c3899a7ec51f220 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2812e95 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild