$ git clone -n https://src.fedoraproject.org/rpms/perl-Acme-Damn.git /var/lib/mock/f45-build-21553-586/root/chroot_tmpdir/scmroot/perl-Acme-Damn
Cloning into '/var/lib/mock/f45-build-21553-586/root/chroot_tmpdir/scmroot/perl-Acme-Damn'...
$ git fetch origin 1e5261eb2f442a3203d4c5ea5dc6a2839431abe3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Acme-Damn
 * [new ref]         1e5261eb2f442a3203d4c5ea5dc6a2839431abe3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1e5261e Perl 5.44 rebuild