$ git clone -n https://src.fedoraproject.org/rpms/perl-Date-Pcalc.git /var/lib/mock/f45-build-23014-595/root/chroot_tmpdir/scmroot/perl-Date-Pcalc
Cloning into '/var/lib/mock/f45-build-23014-595/root/chroot_tmpdir/scmroot/perl-Date-Pcalc'...
$ git fetch origin 2df82b083a1539dc69de18f2e8e788da9594c837:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Date-Pcalc
 * [new ref]         2df82b083a1539dc69de18f2e8e788da9594c837 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2df82b0 Perl 5.44 rebuild