$ git clone -n https://src.fedoraproject.org/rpms/perl-IO-Prompter.git /var/lib/mock/f42-build-side-1-3498993-45964/root/chroot_tmpdir/scmroot/perl-IO-Prompter
Cloning into '/var/lib/mock/f42-build-side-1-3498993-45964/root/chroot_tmpdir/scmroot/perl-IO-Prompter'...
$ git fetch origin c42503ee28541c937f5d1ddf9677eab55df77a80:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-IO-Prompter
 * [new ref]         c42503ee28541c937f5d1ddf9677eab55df77a80 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c42503e New upstream release