$ git clone -n https://src.fedoraproject.org/rpms/perl-Math-Random-MT-Auto.git /var/lib/mock/f43-perl-60951605-6586725/root/chroot_tmpdir/scmroot/perl-Math-Random-MT-Auto
Cloning into '/var/lib/mock/f43-perl-60951605-6586725/root/chroot_tmpdir/scmroot/perl-Math-Random-MT-Auto'...
$ git fetch origin 1b517c2b6368da24127289852577c7a534050272:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Math-Random-MT-Auto
 * [new ref]         1b517c2b6368da24127289852577c7a534050272 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1b517c2 Perl 5.42 rebuild