$ git clone -n https://src.fedoraproject.org/rpms/R-webfakes.git /var/lib/mock/f43-build-side-110352-58909275-6569204/root/chroot_tmpdir/scmroot/R-webfakes
Cloning into '/var/lib/mock/f43-build-side-110352-58909275-6569204/root/chroot_tmpdir/scmroot/R-webfakes'...
$ git fetch origin 868b8166cb0086b3301d5de95b593a54c2f4a410:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-webfakes
 * [new ref]         868b8166cb0086b3301d5de95b593a54c2f4a410 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 868b816 R-maint-sig mass rebuild