$ git clone -n https://src.fedoraproject.org/rpms/perl-IO-Interface.git /var/lib/mock/f43-perl-60958463-6586769/root/chroot_tmpdir/scmroot/perl-IO-Interface
Cloning into '/var/lib/mock/f43-perl-60958463-6586769/root/chroot_tmpdir/scmroot/perl-IO-Interface'...
$ git fetch origin 0b5efe951753c4ab47ecb66ba415190d2e42e8ef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-IO-Interface
 * [new ref]         0b5efe951753c4ab47ecb66ba415190d2e42e8ef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0b5efe9 Perl 5.42 rebuild