$ git clone -n https://src.fedoraproject.org/rpms/golang-github-r3labs-diff-3.git /var/lib/mock/f40-build-2209769-52168/root/chroot_tmpdir/scmroot/golang-github-r3labs-diff-3
Cloning into '/var/lib/mock/f40-build-2209769-52168/root/chroot_tmpdir/scmroot/golang-github-r3labs-diff-3'...
$ git fetch origin cfe01edb01eaa6cd4c07365e2ee317563b2277fc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-r3labs-diff-3
 * [new ref]         cfe01edb01eaa6cd4c07365e2ee317563b2277fc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cfe01ed Initial import