$ git clone -n https://src.fedoraproject.org/rpms/perl-CPAN-Changes.git /var/lib/mock/f40-build-2621881-64812/root/chroot_tmpdir/scmroot/perl-CPAN-Changes
Cloning into '/var/lib/mock/f40-build-2621881-64812/root/chroot_tmpdir/scmroot/perl-CPAN-Changes'...
$ git fetch origin 49e35e79d50fb1a629dfc96412ab5f89bc08b672:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-CPAN-Changes
 * [new ref]         49e35e79d50fb1a629dfc96412ab5f89bc08b672 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 49e35e7 Update to 0.500003