$ git clone -n https://src.fedoraproject.org/rpms/R-timechange.git /var/lib/mock/f38-build-side-42-init-devel-850399-28425/root/chroot_tmpdir/scmroot/R-timechange
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-850399-28425/root/chroot_tmpdir/scmroot/R-timechange'...
$ git fetch origin e4edfefe728fc218cbc8d41b344a25c25be8001e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-timechange
 * [new ref]         e4edfefe728fc218cbc8d41b344a25c25be8001e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e4edfef initial release