$ git clone -n https://src.fedoraproject.org/rpms/R-readr.git /var/lib/mock/f41-build-side-1-2631016-25649/root/chroot_tmpdir/scmroot/R-readr
Cloning into '/var/lib/mock/f41-build-side-1-2631016-25649/root/chroot_tmpdir/scmroot/R-readr'...
$ git fetch origin 6736ceb0db88c1996d5920641153910ccbc77f22:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-readr
 * [new ref]         6736ceb0db88c1996d5920641153910ccbc77f22 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6736ceb convert license to SPDX