$ git clone -n https://src.fedoraproject.org/rpms/perl-PBKDF2-Tiny.git /var/lib/mock/f45-build-25442-611/root/chroot_tmpdir/scmroot/perl-PBKDF2-Tiny
Cloning into '/var/lib/mock/f45-build-25442-611/root/chroot_tmpdir/scmroot/perl-PBKDF2-Tiny'...
$ git fetch origin 470c6252ee82f04f81113702f78f1fcabc8b82cc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-PBKDF2-Tiny
 * [new ref]         470c6252ee82f04f81113702f78f1fcabc8b82cc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 470c625 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild