$ git clone -n https://src.fedoraproject.org/rpms/re2.git /var/lib/mock/f42-build-side-1-3500258-45970/root/chroot_tmpdir/scmroot/re2
Cloning into '/var/lib/mock/f42-build-side-1-3500258-45970/root/chroot_tmpdir/scmroot/re2'...
$ git fetch origin 39d59b966a9be7794018d0517cc5a4330b3505c9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/re2
 * [new ref]         39d59b966a9be7794018d0517cc5a4330b3505c9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 39d59b9 Update comments about dependent packages on i686 again