$ git clone -n https://src.fedoraproject.org/rpms/perl-Sereal-Encoder.git /var/lib/mock/f45-build-26185-616/root/chroot_tmpdir/scmroot/perl-Sereal-Encoder
Cloning into '/var/lib/mock/f45-build-26185-616/root/chroot_tmpdir/scmroot/perl-Sereal-Encoder'...
$ git fetch origin 416f6334d2228c8e0e41b0c1262f56d068e9bc18:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Sereal-Encoder
 * [new ref]         416f6334d2228c8e0e41b0c1262f56d068e9bc18 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 416f633 Update to 5.010 (rhbz#2511546)