$ git clone -n https://src.fedoraproject.org/rpms/perl-Regexp-Stringify.git /var/lib/mock/f45-build-25996-614/root/chroot_tmpdir/scmroot/perl-Regexp-Stringify
Cloning into '/var/lib/mock/f45-build-25996-614/root/chroot_tmpdir/scmroot/perl-Regexp-Stringify'...
$ git fetch origin 8e4bda2e621b372b16c3da396cb9a375c20998d7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Regexp-Stringify
 * [new ref]         8e4bda2e621b372b16c3da396cb9a375c20998d7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8e4bda2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild