$ git clone -n https://src.fedoraproject.org/rpms/R-microbenchmark.git /var/lib/mock/f38-build-724273-99404/root/chroot_tmpdir/scmroot/R-microbenchmark
Cloning into '/var/lib/mock/f38-build-724273-99404/root/chroot_tmpdir/scmroot/R-microbenchmark'...
$ git fetch origin a2fe2d562903a4f24b09a6868f0dc980f8d67062:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-microbenchmark
 * [new ref]         a2fe2d562903a4f24b09a6868f0dc980f8d67062 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a2fe2d5 R-maint-sig mass rebuild