$ git clone -n https://src.fedoraproject.org/rpms/R-lubridate.git /var/lib/mock/f41-build-1280359-23185/root/chroot_tmpdir/scmroot/R-lubridate
Cloning into '/var/lib/mock/f41-build-1280359-23185/root/chroot_tmpdir/scmroot/R-lubridate'...
$ git fetch origin 9a979318e4d2d6926b5d525cd0e68ab602de1fa9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-lubridate
 * [new ref]         9a979318e4d2d6926b5d525cd0e68ab602de1fa9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9a97931 R-maint-sig mass rebuild