$ git clone -n https://src.fedoraproject.org/rpms/perl-PerlIO-Layers.git /var/lib/mock/f45-build-25809-613/root/chroot_tmpdir/scmroot/perl-PerlIO-Layers
Cloning into '/var/lib/mock/f45-build-25809-613/root/chroot_tmpdir/scmroot/perl-PerlIO-Layers'...
$ git fetch origin 4f7beb2a2b415e88642f77f3cc8b8ab2a19b513c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-PerlIO-Layers
 * [new ref]         4f7beb2a2b415e88642f77f3cc8b8ab2a19b513c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4f7beb2 Perl 5.44 rebuild