$ git clone -n https://src.fedoraproject.org/rpms/perl-B-Hooks-OP-Check.git /var/lib/mock/f45-build-21839-588/root/chroot_tmpdir/scmroot/perl-B-Hooks-OP-Check
Cloning into '/var/lib/mock/f45-build-21839-588/root/chroot_tmpdir/scmroot/perl-B-Hooks-OP-Check'...
$ git fetch origin 85a0d93764dd57c9959e88a68e9dcf105afd95f3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-B-Hooks-OP-Check
 * [new ref]         85a0d93764dd57c9959e88a68e9dcf105afd95f3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 85a0d93 Perl 5.44 rebuild